Health Library

The Health Library is a collection of health and wellness resources created for learning and accessibility. Select a topic below for related health information or search for a topic in the search bar for more information on other medical conditions.

Infectious Disease

  • Discusses HIV, a virus that attacks white blood cells called CD4+ cells which are an important part of the immune system. Covers symptoms and stages of infection, including last stage called AIDS (acquired immunodeficiency syndrome). Covers HIV treatment.

  • Guides through decision to treat fluid buildup in the middle ear. Discusses risks and benefits of treatment such as ear tubes, antibiotics, and adenoid surgery. Includes an interactive tool to help you make your decision.

  • The first symptom of Lyme disease in most people is an expanding red skin rash (called erythema migrans or an EM rash). In about a third of people, the rash looks like a bull's-eye, with a pale center area surrounded by a bright red rim. The rash is...

  • Up to 85% of people who are infected with the hepatitis C virus will develop long-term (chronic) infection. About 25% of people who have chronic hepatitis C will go on to develop cirrhosis—severe liver damage and scarring—after a period of...

  • Rapid sputum tests are used to diagnose tuberculosis (TB) when other tests show that a person probably has TB. Rapid sputum tests are also called nucleic acid amplification tests (NAATs). One of the best ways to diagnose TB is through a sputum...

  • Zika virus is a type of virus that is spread by mosquitoes. The mosquitoes that carry Zika are most active during the day but can bite at night. You're more likely to get the virus if you travel to parts of the world where it's more common. This...

  • A yeast infection is usually caused by a fungus called Candida albicans. This kind of yeast naturally lives on your skin. When too much yeast grows, it is called a yeast skin infection. Yeast skin infections tend to happen in skin-to-skin areas....

  • You can help prevent the flu by getting a flu vaccine every year, as soon as it is available. The vaccine prevents most cases of the flu. But even when the vaccine doesn't prevent the flu, it can make symptoms less severe and reduce the chance of...

  • Staphylococcus aureus (staph) is a type of bacteria that can cause infections. Staph bacteria normally live on the skin. They don't usually cause problems. They only become a problem when they cause infection. In most cases, you can treat this...

  • Take a minute to find out what a vaginal yeast infection is and how to treat it.

  • Acute flaccid myelitis (AFM) is a rare condition that affects the spinal cord. It causes certain muscles and reflexes in the body to stop working normally. Anyone can get AFM. A doctor will do a physical exam to check for weakness, such as in the...

  • Find out what sepsis is, how it happens, and how it's treated at the hospital.

  • After a hospital stay, it's important to prevent sepsis and watch for signs of it. Learn how.

  • This article covers the basics of COVID-19, including common symptoms, treatment, the course of the disease, and how to care for yourself.

  • Find out what COVID-19 is, how it's spread, its symptoms, and how to protect yourself and others.

  • Learn how to take care of yourself if you have COVID-19 and find out ways to prevent spreading it to others.

  • Learn how to take care of yourself if you have been exposed to COVID-19 and find out ways to prevent spreading it to others.

  • Learn what social distancing means and why it's important to keep your distance.

  • Discover things you can do to while keeping a social distance.

  • Learn the 5 steps to hand-washing.

  • The coronavirus disease (COVID-19) is caused by a virus. It is an illness that was first found in Wuhan, China, in December 2019. It has since spread worldwide. The virus can cause fever, cough, and trouble breathing. In severe cases, it can cause pneumonia and make it hard to breathe without help. It can cause...

  • During the coronavirus outbreak, learn what to do if you do if you feel sick.

  • You're probably spending a lot of time in your home these days. And that's one place where you have some control. Here are some tips that can help keep you and your home safe from COVID-19. Practice prevention. Wash your hands well and often. Scrub with soap and water for 20 seconds. If you go out...

  • It's normal to feel worried during times of stress. Many people struggle with anxiety in the best of times. Here are some steps you can take to manage anxiety and lower your stress. Get the facts. Go to trusted sources. Check the Centers for Disease Control and Prevention (CDC) website at cdc.gov...

  • Stigma is a negative feeling based on a belief about a group of people. Stigma often occurs when there's a disease outbreak. It's a common human reaction to look for someone to blame when we feel afraid. In the case of COVID-19, some people have blamed it on people of Asian descent or people who have traveled. Some...

  • When experts make a graph of the first wave of COVID-19 infections, it shows a flat line that curves sharply upward, like a ramp at a skateboard park. A steep curve means the virus is spreading fast. That's because each infected person spreads the disease to more than just one other person. Then each of those people...

  • Social distancing means putting space between yourself and other people. The recommended distance is 6 feet, or about 2 meters. This also means staying away from any place where people may gather, such as parks or other public gathering places. Social distancing is the best way to reduce the spread of COVID-19...

  • Many parents are asking, "What are the best ways to protect my child from the virus?" Here are the most powerful steps you can take to protect yourself and your family. Wash hands well and often. Everyone in your household needs to do this. Wash your hands well with soap and water for at least 20...

  • Social distancing is the best way to help keep COVID-19 from spreading. Here are some things you can do while you're putting space between yourself and other people. Be active outside. Fresh air and exercise are good for you. But stay informed about what's best for your community. Keep a 6-foot (or...

  • Find out if you could be at higher risk for COVID-19 and learn how to stay safe.

  • The need to stay at home and limit contact with others is important right now, but it can be lonely and isolating. Loneliness can take a toll on both our mental and physical health. Try these tips to stay connected and positive.

  • There are things you can do to protect your health and the health of your baby. If you're pregnant Pregnancy causes changes in the body that may raise the risk for some infections. Pregnant women are more likely to get seriously ill from respiratory infections, like the flu. So it's important to try to avoid...

  • COVID-19 causes a mild illness in many people who have it. But certain things may increase your risk for more serious illness. These include: Age. The risk increases with age. Older adults are at highest risk. Smoking. Obesity. Living in a long-term care facility. Having ongoing serious...

  • Most people who get COVID-19 will recover with time and home care. Here are some things to know if you're caring for someone who's sick. Treat the symptoms. Common symptoms include a fever, coughing, and feeling short of breath. Urge the person to get extra rest and drink plenty of fluids to replace...

  • Stay home. If you've been exposed, you should stay in quarantine for at least 14 days. Ask your doctor when it's safe to end your quarantine. Don't go to school, work, or public areas. And don't use public transportation, ride-shares, or taxis unless you have no choice. Leave your home only if you need to get...

  • Stay home. Don't go to school, work, or public areas. And don't use public transportation, ride-shares, or taxis unless you have no choice. Leave your home only if you need to get medical care. But call the doctor's office first so they know you're coming. And wear a cloth face cover. Ask before leaving...

  • This is a very stressful time. You may be worried about getting COVID-19 or afraid that someone you care about will get it. If you've lost your job, you may be anxious about your finances. On top of that, you're probably stuck at home. Cabin fever can set in. You may feel trapped, bored, and irritable. Cabin fever...

  • A COVID-19 viral test is a way to find out if you have COVID-19. The test looks for the virus in your breathing passages. There are different types of viral tests. One type looks for genetic material from the virus. This is usually called polymerase chain reaction (PCR). Another type looks for proteins on the...

  • An antibody test looks for antibodies in the blood. These are proteins that your immune system makes, usually after you're exposed to germs like viruses or bacteria or after you get a vaccine. Antibodies work to fight illness. A COVID-19 antibody test looks for antibodies to SARS-CoV-2, the virus that causes...

  • Multisystem Inflammatory Syndrome in Children (MIS-C) Multisystem inflammatory syndrome in children (MIS-C) is a rare but serious condition. It causes inflammation, which can affect the heart, lungs, brain, and other organs. A child usually has a fever for 24 hours or longer, plus other symptoms. These can vary, but...

  • This article describes the measures that health care providers take to help ensure your safety as well as steps you can take to reduce your risk of infection in the hospital or clinic.

  • Learn how to wear a cloth face cover or a mask to help stop the spread of COVID-19.

  • Learn three reasons why you shouldn't try to get infected with COVID-19 on purpose.

  • Learn about the risk levels for getting infected or infecting others with COVID-19 during different activities.

  • Learn the difference between symptoms of the flu and COVID-19.

  • This topic helps readers assess whether they may have a drinking problem.

  • Find ways to stay connected when you can't be together.

  • Learn about ways to show care and compassion to yourself.

  • Learn ways to exercise at home during the pandemic.

  • This article helps you learn how to handle stress in your relationship.

  • Learn some ways to manage family stress.

  • This article helps parents learn how to lower stress during the pandemic.

  • Learn how to overcome barriers to wearing a mask.

  • Learn some tips for helping to manage money problems.

  • Learn some new tips for having date night at home during the pandemic.

  • Learn about the vaccine for COVID-19.

  • This article helps readers understand when a home pulse oximeter is helpful for people who have COVID-19 and how to use it.

  • Learn what effects COVID-19 may have on the body long after recovery.

  • DTaP vaccine can prevent diphtheria, tetanus, and Pertussis. Diphtheria and pertussis spread from person to person. Tetanus enters the body through cuts or wounds. DIPHTHERIA (D) can lead to difficulty breathing, heart failure, paralysis, or death. TETANUS (T) causes painful stiffening of the muscles...

  • Hepatitis A is a serious liver disease. It is caused by the hepatitis A virus (HAV). HAV is spread from person to person through contact with the feces (stool) of people who are infected, which can easily happen if someone does not wash his or her hands properly. You can also get hepatitis A from food, water, or object…

  • Hepatitis B vaccine can prevent hepatitis B. Hepatitis B is a liver disease that can cause mild illness lasting a few weeks, or it can lead to a serious, long illness. Acute hepatitis B infection is a short-term illness that can lead to fever, fatigue, loss of appetite, nausea, vomiting, jaundice...

  • Influenza vaccine can prevent influenza (flu). Flu is a contagious disease that spreads around the United States every year, usually between October and May. Anyone can get the flu, but it is more dangerous for some people. Infants and young children, people 65 years of age and older, pregnant women...

  • Influenza vaccine can prevent influenza (flu). Flu is a contagious disease that spreads around the United States every year, usually between October and May. Anyone can get the flu, but it is more dangerous for some people. Infants and young children, people 65 years of age and older, pregnant women...

  • MMR vaccine can prevent measles, mumps, and rubella. MEASLES (M) can cause fever, cough, runny nose,and red, watery eyes, commonly followed by a rash that covers the whole body. It can lead to seizures (often associated with fever), ear infections, diarrhea, and pneumonia. Rarely, measles can cause brain damage or death...

  • Meningococcal ACWY vaccine can help protect against meningococcal disease caused by serogroups A, C, W, and Y. A different meningococcal vaccine is available that can help protect against serogroup B. Meningococcal disease can cause meningitis (infection of the lining of the brain and spinal cord)...

  • Pneumococcal polysaccharide vaccine (PPSV23) can prevent pneumococcal disease. Pneumococcal disease refers to any illness caused by pneumococcal bacteria. These bacteria can cause many types of illnesses, including pneumonia, which is an infection of the lungs. Pneumococcal bacteria are one of the...

  • Pneumococcal conjugate vaccine (PCV13) can prevent pneumococcal disease. Pneumococcal disease refers to any illness caused by pneumococcal bacteria. These bacteria can cause many types of illnesses, including pneumonia, which is an infection of the lungs. Pneumococcal bacteria are one of the most…

  • Polio vaccine can prevent polio. Polio (or poliomyelitis) is a disabling and life-threatening disease caused by poliovirus, which can infect a person's spinal cord, leading to paralysis. Most people infected with poliovirus have no symptoms, and many recover without complications...

  • Rabies vaccine can prevent rabies. Rabies is mainly a disease of animals. Humans get rabies when they are bitten or scratched by infected animals. Human rabies is rare in the United States. Wild animals like bats, raccoons, skunks, and foxes are the most common source of human rabies infection in the United…

  • Td vaccine can prevent tetanus and diphtheria. Tetanus enters the body through cuts or wounds. Diphtheria spreads from person to person. TETANUS (T) causes painful stiffening of the muscles. Tetanus can lead to serious health problems, including being unable to open the mouth, having trouble swallowing...

  • Tdap vaccine can prevent tetanus, diphtheria, and pertussis. Diphtheria and pertussis spread from person to person. Tetanus enters the body through cuts or wounds. TETANUS (T) causes painful stiffening of the muscles. Tetanus can lead to serious health problems, including being unable to open the mouth...

  • Typhoid vaccine can prevent typhoid fever. People who are actively ill with typhoid fever and people who are carriers of the bacteria that cause typhoid fever can both spread the bacteria to other people. When someone eats or drinks contaminated food or drink, the bacteria can multiply and spread into the bloodstream...

  • Varicella vaccine can prevent chickenpox. Chickenpox can cause an itchy rash that usually lasts about a week. It can also cause fever, tiredness, loss of appetite, and headache. It can lead to skin infections, pneumonia, inflammation of the blood vessels, and swelling of the brain and/or spinal...

  • Yellow fever vaccine can prevent yellow fever. Yellow fever is a serious disease caused by the yellow fever virus. There is no medicine to treat or cure yellow fever. Yellow fever virus is spread by the bite of an infected mosquito. It is found in parts of Africa and South America…

  • Rotavirus vaccine can prevent rotavirus disease. Rotavirus causes diarrhea, mostly in babies and young children. The diarrhea can be severe, and lead to dehydration. Vomiting and fever are also common in babies with rotavirus. Rotavirus vaccine Rotavirus vaccine is administered by putting drops in the child's mouth...

  • Live zoster (shingles) vaccine can prevent shingles. Shingles (also called herpes zoster, or just zoster) is a painful skin rash, usually with blisters. In addition to the rash, shingles can cause fever, headache, chills, or upset stomach. More rarely, shingles can lead to pneumonia, hearing problems...

  • Japanese encephalitis (JE) vaccine can prevent Japanese encephalitis. Japanese encephalitis occurs mainly in many parts of Asia and the Western Pacific, particularly in rural areas. It is spread through the bite of an infected mosquito. It does not spread from person to person. Risk is very low for most travelers.

  • MMRV vaccine can prevent measles, mumps, rubella, and varicella. MEASLES (M) can cause fever, cough, runny nose, and red, watery eyes, commonly followed by a rash that covers the whole body. It can lead to seizures (often associated with fever), ear infections, diarrhea, and pneumonia. Rarely, measles...

  • The vaccines included on this statement are likely to be given at the same time during infancy and early childhood. There are separate Vaccine Information Statements for other vaccines that are also routinely recommended for young children (measles, mumps, rubella, varicella, rotavirus, influenza, and hepatitis A).

  • HPV (Human papillomavirus) vaccine can prevent infection with some types of human papillomavirus. HPV infections can cause certain types of cancers including: cervical, vaginal and vulvar cancers in women, penile cancer in men, and anal cancers in both men and women HPV vaccine prevents infection...

  • Meningococcal B vaccine can help protect against meningococcal disease caused by serogroup B. A different meningococcal vaccine is available that can help protect against serogroups A, C, W, and Y. Meningococcal disease can cause meningitis (infection of the lining of the brain...

  • Cholera vaccine can prevent cholera. Cholera is spread through contaminated food or water. It is not usually spread directly from person to person, but it can be spread through contact with the feces of an infected person. Cholera causes severe diarrhea and vomiting. If it isn't treated quickly...

  • Recombinant zoster (shingles) vaccine can prevent shingles. Shingles (also called herpes zoster, or just zoster) is a painful skin rash, usually with blisters. In addition to the rash, shingles can cause fever, headache, chills, or upset stomach. More rarely, shingles can lead to pneumonia...

  • Links to information on colds and flu. Covers at-home treatment for cold and flu symptoms, the flu vaccine, prevention of colds and flu, and medicines for the flu.

  • Helicobacter pylori is a type of bacteria that is a major cause of stomach (gastric) and upper small intestine (duodenal) ulcers. Infection with H. pylori may also increase the risk of stomach cancer. H. pylori bacteria can cause ulcers by growing in the lining of the stomach, producing inflammation and causing...

  • An antibiotic sensitivity (or susceptibility) test is done to help choose the antibiotic that will be most effective against the specific types of bacteria or fungus infecting an individual person. Some types of bacteria or fungus are resistant to...

  • Topic guides you through the decision to get the shingles vaccine. Explains your chances of getting shingles and how well the vaccine works. Lists risks and benefits of getting the vaccine. Includes interactive tool to help you make your decision.

  • What is dengue fever? Dengue (say "DEN-gay") fever is a disease caused by a virus that is carried by mosquitoes. Mild cases cause a rash and flu-like symptoms. Some people, especially children, can get more serious forms of the illness, known as dengue hemorrhagic fever and dengue shock syndrome. What...

  • Hepatitis E is a virus that can infect the liver. Unlike other forms of hepatitis, the hepatitis E virus usually doesn't lead to long-term illness or serious liver damage. Most people get well within a few months. People usually get hepatitis E by...

  • Guides through the decision to be screened for sexually transmitted infections. Explains STIs and discusses causes and lifestyles that put you at higher risk for getting infected. Covers benefits and risks of testing. Includes an interactive tool to help you decide.

  • Guides through the decision to be screened for an HIV infection. Explains HIV and discusses causes and lifestyles that put you at higher risk for getting infected. Covers benefits and risks. Includes an interactive tool to help you make your decision.

  • HIV (human immunodeficiency virus) is a virus that attacks the immune system, the body's natural defense system. Without a strong immune system, the body has trouble fighting off disease. Both the virus and the infection it causes are called HIV....

  • If your doctor wants you to be kept away, or isolated, from other patients while you receive medical care, you may be in a special hospital room, called an isolation room, to keep you separate from other people. This may be done because you have an...

  • Hospitals are full of sick people, so they have a lot of germs. And although health care workers do their best to kill germs and protect patients, they can't always prevent infections. Hospital infections can be very serious, especially if you're...

  • When you spend time around an animal—whether it's a pet, a farm animal, or a wild animal—there's a chance you can pick up an infection. An infection you get from an animal is called a zoonosis (say "zoh-uh-NOH-sus"). Some infections can seem mild,...

  • Learn how to wash so you won't spread the rash.

  • Find out the important things that happen for you and others when you get the flu vaccine.

  • Learn why you probably don't need an antibiotic when you have acute bronchitis.

  • Learn why antibiotics shouldn't be prescribed to children who have a cold or flu.

  • Guides through decision to get the HPV vaccine. Explains the vaccination process. Covers benefits and risks. Includes an interactive tool to help you make your decision.

  • Learn how to prevent the spread of germs and avoid infections in the hospital.

  • Understand how an isolation room protects you and those around you.

  • Learn three important ways to prepare for a healthier hospital stay.

  • Learn how the pneumococcal vaccine protects you from serious infections.

  • Learn what you can do at home to help yourself get better from pneumonia.

  • Germs and infection can spread easily in the home. This may happen when items around the house become soiled or when you come into contact with body fluids, such as blood or urine. A person's cough or sneeze can spread germs too. Washing your hands often can help you keep germs and infection from spreading...

  • Keeping clothes and bed linens clean can take time, but it's worth the effort. It can help the person you're caring for stay healthy and feel clean. Clothes and bed linens become soiled when they come into contact with things like urine, stool, or vomit. Washing soiled clothes and linens right away can help...

  • Learn what is checked during an HIV test, who might need one, and what the results may mean.

  • Chikungunya (say "chick-un-GOON-ya") fever is an illness caused by a virus that is carried by mosquitoes. You're more likely to get this illness if you travel to parts of the world where it's more common. This includes parts of Africa, Europe, and...

  • Middle East respiratory syndrome (MERS) is an illness that was first found in Saudi Arabia in 2012 and has since spread to other countries. It's caused by a type of coronavirus that can cause a moderate to severe upper respiratory illness such as the common cold. The virus is known as MERS-CoV. Experts believe MERS may...

  • The flu and the common cold are both types of upper respiratory infections (URIs). Both are caused by viruses. But the flu is not the same as the common cold. Flu symptoms are usually much worse than a cold. The flu usually comes on suddenly and...

  • The loop electrosurgical excision procedure (LEEP) uses a thin, low-voltage electrified wire loop to remove genital warts by heating the margin of the area to be removed, which separates the wart from the skin. LEEP is done in a doctor's office, clinic, or hospital on an outpatient basis. A local anesthetic is injected...

  • What is a pseudomonas infection? A pseudomonas infection is caused by a very common type of bacteria called Pseudomonas aeruginosa (say "soo-duh-MOH-nuss ay-roo-jee-NOH-suh"). Healthy people often carry these bacteria around without knowing it and without having any problems. Sometimes these germs cause minor...

  • Jock itch (tinea cruris) is a form of ringworm. Ringworm is not a worm at all. It is a fungal infection of the outer layers of skin, hair, or nails. Fungi (plural of fungus) are present everywhere in our environment. Ringworm of the skin appears as...

  • Guides you through decision to take medicine for nail fungal infection. Explains fungal infections and why treatment might be needed. Lists other treatments. Includes interactive tool to help you make your decision.

  • Some women carry group B streptococcus bacteria in the vagina. And for some of them, it does not cause problems. (This type of strep is not the same as the type that causes strep throat.) But a woman who has group B strep in her vagina can pass it...

  • What is meningitis? Meningitis is inflammation of the lining around the brain and spinal cord. It is usually caused by an infection. The infection occurs most often in children, teens, and young adults. Also at risk are older adults and people who have long-term health problems, such as a weakened immune system...

  • Meningitis caused by Neisseria meningitidis is sometimes referred to as meningococcal disease. Some people have Neisseria meningitidis in their throats without getting sick. But they can pass it to another person, who may get sick. Neisseria...

  • What is traveler's diarrhea? Traveler's diarrhea is a common medical problem for people traveling from developed, industrialized countries to developing areas of the world. High-risk areas for traveler's diarrhea include developing countries in Africa, Asia, the Middle East, and Latin America. Low-risk areas...

  • Rabies immune globulin is used to protect people who have been bitten by animals (post-exposure). This medicine is given together with a full series of rabies vaccination. Rabies immune globulin by itself will not protect against rabies. You will not need rabies immune globulin if you have received a rabies vaccine in...

  • COVID-19 is a serious disease caused by a coronavirus called SARS-CoV-2 (Serious Acute Respiratory Syndrome Coronavirus 2). Coronaviruses are common causes of illness worldwide. COVID-19 is a type of coronavirus never seen in humans before 2019. COVID-19 is spread from person to person through the air. COVID-19 can...

  • A vaginal yeast infection is thought to be recurrent when: You have had four or more infections within 1 year. The infections have caused symptoms. The infections are not related to the use of antibiotics. If you have a recurrent vaginal yeast...

  • A hip problem can be hard to deal with, both for the child who has the problem and to the parent or caregiver. A child who has a hip problem may feel pain in the hip, groin, thigh, or knee. A child in pain may limp or be unable or unwilling to...

  • Hip pain can make it hard to walk, go up and down stairs, squat, or sleep on the side that hurts. A clicking or snapping feeling or sound around your hip joint (snapping hip) may bother you or cause you to worry. But if your hip is not painful, in many cases the click or snap is nothing to worry about. Home treatment...

  • What is fifth disease? Fifth disease is a very common childhood illness. Adults can get it too. It is sometimes called slapped-cheek disease because of the rash that some people get on the face. You spread the disease by coughing and sneezing. Fifth disease is usually a mild illness that lasts a few weeks. It...

  • Cryotherapy (cryosurgery) destroys genital warts by freezing them with liquid nitrogen. A doctor applies liquid nitrogen to and around the warts. First, the tissue is frozen with liquid nitrogen. Then, the tissue is allowed to thaw. The tissue is frozen again, if needed. The time of application varies by the doctor...

  • A laser can be used to destroy genital warts. Laser surgery may be done in a doctor's office or clinic, a hospital, or an outpatient surgery center. Local or general anesthetic may be used depending on the number of warts to be removed or the size of the area to be treated. For women, abnormal cervical cell changes...

  • Your doctor may take a sample, or biopsy, of abnormal tissue. The majority of warts do not require a biopsy. But a biopsy may be taken if genital warts cannot be easily identified with a physical exam or during a gynecology exam with a lighted magnifying instrument ( colposcopy). A microscopic exam on the biopsied...

  • Covers causes and symptoms of human papillomavirus (HPV), a sexually transmitted infection (STI). HPV is also called genital warts. Looks at treatment with medicines, lasers, surgery, or freezing. Covers prevention and shots of HPV vaccine.

  • Doctors use thick and thin blood smears to determine whether you have malaria. If one test is negative and no parasites are found, you will have repeated blood smears every 8 hours for a couple of days to confirm that there is no malaria infection. Blood smears are taken most often from a finger prick. Thick and thin...

  • What is malaria? Malaria is a serious disease that causes a fever and other flu-like symptoms. You can get it from a bite by an infected mosquito. Malaria is rare in the United States. It is found in over 90 countries around the world, mainly in Africa, Asia, Oceania, South America, and Central America. The risk of...

  • Although most cases of influenza (flu) get better without causing other problems, complications sometimes develop. Possible complications of flu include: Pneumonia, which is an inflammation of the lungs. Primary influenza viral pneumonia develops...

  • Many people choose not to have the influenza vaccine because of myths they believe about the disease or the vaccine. Myth: Influenza is a minor illness. Truth: Influenza and its complications caused from 3,000 to 49,000 deaths each year from 1976 to...

  • Discusses symptoms of the flu, which is caused by the influenza virus. Covers how it's spread and when people who have the flu are contagious. Discusses prevention, including getting the influenza vaccine. Offers home treatment tips.

  • Immunization against the hepatitis A virus (HAV) is recommended for anyone traveling to any country or area except: Australia. Canada. Japan. New Zealand. The United States. Western Europe and the Scandinavian countries (Norway, Sweden, and Finland). Talk to your doctor...

  • What is hepatitis A? Hepatitis A is a virus that can infect the liver. In most cases, the infection goes away on its own and doesn't lead to long-term liver problems. In rare cases, it can be more serious. Other viruses ( hepatitis B and hepatitis C) also can cause hepatitis. Hepatitis A is the most common type...

  • What is an E. coli infection? E. coli ( Escherichia coli) is the name of a germ, or bacterium, that lives in the digestive tracts of humans and animals. There are many types of E. coli, and most of them are harmless. But some can cause bloody diarrhea. Some strains of E. coli bacteria may also cause severe...

  • What is thrush? Thrush is a yeast infection that causes white patches in the mouth and on the tongue. Thrush is most common in babies and older adults, but it can occur at any age. Thrush in babies is usually not serious. What causes thrush? You get thrush when a yeast called Candida, normally found on the body...

  • What is toxic shock syndrome? Toxic shock syndrome (TSS) is a rare illness that happens suddenly after an infection. It quickly can harm several different organs, including the lungs, the kidneys, and the liver, and it can be deadly. Since toxic shock syndrome gets worse quickly, it requires medical treatment right...

  • Discusses rare flesh-eating bacterial infection. Includes info on Fournier gangrene. Covers symptoms and how it is diagnosed. Looks at treatment with medicine, surgery, and oxygen therapy. Covers treatment for complications caused by the infection.

  • Viral hepatitis is liver inflammation caused by infection with a virus. The following viruses cause most cases of viral hepatitis: Hepatitis A virus (HAV) Hepatitis B virus (HBV) Hepatitis C virus (HCV) Hepatitis D virus (HDV) Hepatitis E virus...

  • Discusses hepatitis C, a disease caused by a virus that infects the liver. Covers causes and symptoms. Includes info on the two phases, acute and chronic. Includes info on cirrhosis. Covers treatment with antiviral medicines and surgery.

  • What is encephalitis? Encephalitis is inflammation of the brain. This inflammation can cause symptoms such as confusion, a fever, a bad headache, and a stiff neck. Sometimes it leads to symptoms like seizures and personality changes. It can also cause long-term problems, such as trouble with speech or memory...

  • Most people recover from mononucleosis (mono) without any complications. But there are many possible complications of mono. These include: An enlarged spleen, which occurs in up to 75 out of 100 people who have mono. Red spots or rash,...

  • Discusses mononucleosis (also called mono or the kissing disease) caused by Epstein-Barr virus (EBV). Covers symptoms including high fever, severe sore throat, and swollen lymph nodes (swollen glands), tonsils, and spleen. Offers home treatment and prevention tips.

  • Viral load is a measurement of how much HIV is present in your blood. A sample of blood is drawn and sent to a lab for testing. Results are expressed as the number of copies of the virus per milliliter of blood. Each virus is called a "copy" because...

  • What is mumps? Mumps is a contagious viral infection that can cause painful swelling of the salivary glands, especially the parotid glands (between the ear and the jaw). Some people with mumps won't have gland swelling. They may feel like they have a bad cold or the flu instead. Mumps usually goes away on its...

  • What is rabies? Rabies is an infection caused by a virus. It affects the brain and spinal cord ( central nervous system) of mammals, including humans. It is nearly always deadly if not treated before symptoms begin. Animals that are infected with rabies—rabid animals—can spread the disease through their saliva...

  • What is rubella? Rubella is a very contagious (easily spread) illness caused by the rubella virus. It is usually a mild illness. But in rare cases, it may cause more serious problems. If you are pregnant and get infected with the rubella virus, your baby (fetus) could become infected too. This can cause birth...

  • The U.S. Centers for Disease Control and Prevention (CDC) classifies untreated HIV infection into three stages: CDC stages of HIV infection Acute retroviral syndrome: This is an illness with symptoms like mononucleosis. It often develops within a few days of infection with HIV, but it also may...

  • For a giardia antigen test, a stool sample or fluid from the upper part of the intestines (duodenal fluid) is tested in the lab for the presence of antigens from Giardia lamblia. This test is often done at the same time as a stool analysis.

  • What is giardiasis? Giardiasis (say "jee-ar-DYE-uh-sus") is an infection of the intestines caused by the parasite Giardia lamblia. The illness, also called giardia (say "jee-AR-dee-uh"), is most often a problem in undeveloped countries where tap water is not safe. How can you become infected with giardia? You may...

  • CD4+ cells are part of the immune system and are a type of white blood cell. White blood cells protect the body against infection. CD4+ cells are also called T-lymphocytes, T-cells, or T-helper cells. HIV invades and destroys CD4+ cells. But the...

  • Health professionals are not considered at high risk for HIV infection, because they use protection (such as gloves, masks, and goggles) when dealing with blood or body fluids. The chances of becoming infected after being stuck or cut with an instrument that is contaminated with HIV-infected blood are about 1...

  • HIV does not survive well outside the body. HIV cannot be spread from one person to another in any of the following ways: Casual contact In studies of hundreds of households in which families have lived with and cared for people who have AIDS, including situations in which no one knew that the person...

  • Eating a nutritious, balanced diet is an important part of treating HIV. Good nutrition can help your immune system stay strong, which in turn may help your body fight HIV. Knowing the best way to nourish your body will help keep it strong and allow...

  • What is hantavirus pulmonary syndrome? Hantavirus pulmonary syndrome (HPS) is a lung infection caused by viruses found in the saliva, urine, and droppings of some rodents. The illness is rare but can be deadly. What causes HPS? Most cases of HPS in the U.S. are caused by one type of hantavirus found in the deer...

  • Exercise can't control the HIV infection. But exercise may help you feel better by reducing stress. Exercise may also help your immune system work better. Exercise: Is safe. Improves strength and endurance. Improves heart and lung fitness. May help...

  • It is important to think about the emotional well-being of the person with HIV you care for. Because every person's emotional needs are different, no single approach is best for everybody. Encourage the person to become involved in medical decisions...

  • HIV is present in the blood, semen, and vaginal fluids of a person who is infected with HIV and is usually spread by: Unprotected sex (vaginal, anal, or oral) with a person who is infected with HIV. Using condoms is the only way to prevent getting...

  • A person who has HIV has difficulty fighting off other infections. You can help protect the person from infections. Avoid close contact with people who have contagious illnesses until their symptoms have disappeared. This includes illnesses such as...

  • Providing support for a person who has AIDS can be a stressful and emotional experience. You may feel frustrated if the person doesn't want to take all of the medicine prescribed or if he or she doesn't get better despite your efforts. To help...

  • If a person's HIV infection progresses, you may be called on to provide home care for that person. A home care course may give you the knowledge, skills, and confidence to provide the care needed. Contact your local Red Cross chapter, Visiting Nurse...

  • What is syphilis? Syphilis is a sexually transmitted infection (STI) caused by the bacterium Treponema pallidum. If it's not treated by a doctor, it can get worse over time and cause serious health problems. The infection can be active at times and not active at other times. When the infection is active, you...

  • Neurosyphilis refers to the infection of the brain and spinal cord by the syphilis bacteria. This can lead to destruction in many areas of the nervous system, causing loss of function of a person's arms or legs, loss of vision, and altered mental...

  • Congenital syphilis occurs when a mother's syphilis goes untreated during pregnancy and is passed to the baby through the placenta. A baby can also become infected with syphilis during labor or delivery. The risk of infecting the baby is greatest...

  • What is measles? Measles is a very contagious (easily spread) infection that causes a rash all over your body. It is also called rubeola or red measles. The measles vaccine protects against the illness. This vaccine is part of the MMR (measles, mumps, and rubella) and MMRV (measles, mumps, rubella, and varicella...

  • Doctors often prescribe antibiotics to treat severe acne or acne that is likely to leave scars. Antibiotics improve the look of your skin by killing bacteria that cause acne. This means you'll have fewer pimples and redness. Less acne means less...

  • Covers hepatitis B virus (HBV) tests that check for hepatitis B infection. Looks at most common HBV tests. Explains how tests are done and how to prepare for them. Looks at other tests that show how well the liver is working. Covers test results.

  • What is tuberculosis? Tuberculosis (TB) is an infection caused by slow-growing bacteria that grow best in areas of the body that have lots of blood and oxygen. That's why it is most often found in the lungs. This is called pulmonary TB. But TB can also spread to other parts of the body, which is called...

  • Scratching chickenpox blisters can lead to skin infections, not to mention scarring. In rare cases, infected chickenpox lesions can lead to toxic shock syndrome. To keep children from scratching chickenpox blisters: Clean and closely trim your...

  • Discusses vaccine-preventable illness that causes itchy rash and red spots or blisters (pox) all over the body. Covers home treatment, including resting and taking medicines to reduce fever, itching. Includes info on shingles.

  • Sepsis is a life-threatening reaction to an infection. It causes inflammation across large areas of the body and can damage tissue and organs. Sepsis requires immediate care in a hospital. Septic shock is sepsis that causes extremely low blood...

  • Electrocautery removes genital warts on the penis, vulva, or around the anus by burning them with a low-voltage electrified probe. Electrocautery is usually done in a doctor's office or a clinic. The injection of a numbing medicine ( local anesthetic) is usually used for pain control. Medicine that causes...

  • Visible genital warts on the penis or vagina or around the anus are removed by excision, which means cutting the warts off with a surgical knife (scalpel). Warts on the cervix may be removed by laser or loop electrosurgical excision (LEEP). The procedure is usually done in a doctor's office or clinic or an outpatient...

  • A bacterial infection may develop following infection with viral influenza. Signs of a bacterial infection include: Feeling short of breath. A fever that doesn't go away. A cough that lingers more than 7 to 10 days after other symptoms have...

  • If you were exposed to ticks and you get an expanding, circular rash (erythema migrans), your doctor may treat you for Lyme disease without doing a blood test. Blood tests done in the first few weeks may not show Lyme disease even when you have the illness. This is because the body's immune system responds slowly to the...

  • Other tests for lung infections, such as pneumonia and acute bronchitis, may include: Blood tests or cultures. Blood tests may help tell whether antibodies to a specific organism that can cause pneumonia are present or whether specific viruses, such as influenza (flu) or respiratory syncytial virus (RSV)...

  • Common problems may develop with artificial nails, such as: Bacterial infection. You may dislodge an artificial nail from the nail bed by bumping it or catching it. Infection can develop in the gap that forms between the two nails, especially if the...

  • What is a fungal nail infection? A fungal nail infection occurs when a fungus attacks a fingernail, a toenail, or the skin under the nail, called the nail bed. Fungi (plural of fungus) can attack your nails through small cuts in the skin around your nail or through the opening between your nail and nail bed. If you...

  • Nonsurgical (chemical) nail removal is a painless procedure for a fungal nail infection. This technique removes only the diseased and damaged nail, not the healthy part of the nail. It is done in a clinic or your doctor's office. Either the entire nail (avulsion) or part of the nail (debridement) can be removed. This...

  • Surgical nail removal can be done for severe or returning fungal nail infections. The entire nail (avulsion) or only part of the nail (debridement) can be removed. Surgical nail removal can be done in a clinic or your doctor's office. Your doctor will give you an injection in the finger or toe to prevent pain. He or...

  • Discusses causes and symptoms of athlete's foot. Lists behaviors that increase risk. Covers when to see doctor. Covers treatment options, including medicine choices. Offers home treatment and prevention tips.

  • People who are infected with hepatitis B virus (HBV) or hepatitis C (HCV) virus may develop a chronic infection that can lead to cirrhosis. The damage that results increases the risk of liver cancer (hepatocellular carcinoma). If you have chronic...

  • Infection with the hepatitis D virus (HDV), or delta agent, occurs only in people who are already infected with the hepatitis B virus (HBV). HDV infection may make HBV infection more severe. In people who have long-term (chronic) HBV infection, HDV infection can make liver disease worse. Or it can cause a...

  • The following tips can help you prevent the spread of the hepatitis B virus (HBV). Inform the people you live with and/or have sex with about your illness as soon as possible. If you have long-term (chronic) HBV infection, you can infect others with the virus even if you have no symptoms of illness. Do not...

  • What is hepatitis B? Hepatitis B is a virus that infects the liver. Most adults who get it have it for a short time and then get better. This is called acute hepatitis B. Sometimes the virus causes a long-term infection, called chronic hepatitis B. Over time, it can damage your liver. Babies and young children...

  • If you have heart failure, it is important that you do as much as possible to avoid catching colds, the flu, and other respiratory infections. Although these may be relatively minor illnesses in healthy people, they are more dangerous if you have heart failure, and you are at higher risk for dangerous complications...

  • A human immunodeficiency virus (HIV) test detects HIV antibodies or antigens, or the genetic material ( DNA or RNA) of HIV in the blood or another type of sample. This can show if an HIV infection is present (HIV-positive). HIV infects white blood cells called CD4+ cells. They are part of the body's immune system that...

  • Pinworms are a type of parasite that lives in the digestive system of humans. They are common throughout the world. Adult pinworms are about 0.5 in. (12.7 mm) long and look like little white threads. Pinworm eggs are so tiny, you'd need a microscope...

  • Discusses antibody test used to detect Lyme disease. Covers two types of test (enzyme-linked immunosorbent assay and Western blot test). Covers why and how they are done. Includes info on what results mean.

  • Covers monospot test (heterophil test) and EBV antibody test, blood tests used to diagnose mononucleosis (mono), which is caused by the Epstein-Barr virus. Covers how it is done and risks. Also includes info on what test results might mean.

  • A rubella blood test detects antibodies that are made by the immune system to help kill the rubella virus. These antibodies remain in the bloodstream for years. The presence of certain antibodies means a recent infection, a past infection, or that you have been vaccinated against the disease. Rubella (also called...

  • Syphilis tests tell if a person has this disease. They look for antibodies to the bacterium, or germ, that causes syphilis. Some tests look for the syphilis germ itself. Syphilis is a sexually transmitted infection. That means it is spread through sexual contact: vaginal, anal, or oral sex. Testing is done on...

  • Discusses toxoplasmosis test, a blood test that checks pregnant women for antibodies to the Toxoplasma gondii parasite. Covers why and how it is done. Also discusses what results mean.

  • Discusses infection caused by overgrowth of Candida albicans, a type of yeast that normally lives in the vagina. Covers symptoms like itching or soreness in vagina or burning when you urinate or have sex. Looks at treatment with medicines like Monistat.

  • Antibiotics are medicines that kill bacteria. Bacteria can cause infections such as strep throat, ear infections, urinary tract infections, and sinus infections (sinusitis). There are many types of antibiotics. Each works a little differently and...

  • Discusses pneumonia, a lung infection caused by bacteria. Covers mild symptoms of walking pneumonia and more severe symptoms of other types of pneumonia. Discusses tests used to diagnose pneumonia. Includes info on treatment using antibiotics.

  • Explains ringworm causes, symptoms, and progression. Covers how it is diagnosed and treated. Includes information on medicines. Covers behaviors that increase risk of ringworm. Offers prevention and home treatment tips.

  • Is this topic for you? This topic is about ringworm of the scalp or beard. To learn more about other fungal infections, see the topics: Athlete's Foot. Diaper Rash. Fungal Nail Infections. Ringworm of the Skin. What is ringworm of the scalp or beard? Ringworm is an infection on your skin, hair, or nails...

  • Whooping cough (pertussis) is a disease that causes very severe coughing that may last for months. During bursts of violent coughing, you may make a noise that sounds like a "whoop" when you try to take a breath. You can cough so hard that you hurt...

  • Misdiagnosis of Lyme disease is common. The bacteria that cause the illness are hard to detect with current lab tests. People often test positive for Lyme disease when in fact they have a different bacterial illness. People may test positive because...

  • Discusses shingles, a condition caused by the virus that causes chickenpox (herpes zoster). Discusses who is most likely to get it. Describes how shingles rash causes pain and the treatment for it. Includes info on the shingles vaccine.

  • Discusses Lyme disease, an infection spread by ticks. Includes info on deer ticks. Covers symptoms and Lyme disease tests. Covers treatment with antibiotics. Includes info on complications from not treating Lyme disease. Offers prevention tips.

  • Vaginal yeast infections are a common problem during pregnancy. They may be caused by high estrogen levels. These infections aren't a risk to the pregnancy. But they can cause uncomfortable symptoms. If you are pregnant and have vaginal infection...

  • What is an enterovirus D68 infection? Enterovirus D68 is an infection in the lungs and breathing passages (respiratory system). It is caused by a virus called enterovirus D68 (EV-D68). This is one of many kinds of enteroviruses. Enterovirus infections usually cause mild, cold-like symptoms. But an enterovirus D68...

  • What is an Ebola or Marburg virus infection? Ebola and Marburg virus diseases are rare but often deadly diseases that are caused by the Ebola or Marburg virus. A person who is sick with one of these viruses can spread the infection to others. These are known as hemorrhagic viruses, because they can cause severe...

  • It is not unusual to have a problem with your mouth from time to time. A mouth problem can involve your gums, lips, tongue, or inner cheeks, the roof of your mouth (soft and hard palates), under your tongue, your neck, or your teeth. Your mouth may...

  • Minor fingernail and toenail problems are common. At one time or another, almost everyone has caught a nail on something, causing it to rip, or has smashed a finger in a door, leaving blood under the nail. These kinds of injuries can be quite painful but are usually not serious. You can often relieve pain and prevent...

  • Try home treatment if you think you have an infection in the skin around your nail. Soak your foot or hand 2 to 3 times each day in a solution of 1 tsp (5 g) of salt dissolved in 4 cups (1 L) warm water. After soaking, apply a thin layer of petroleum jelly, such as Vaseline, and a bandage. Do not try to...

  • What are the most important things you need to know about your medicines? Make sure you know about each of the medicines you take. This includes why you take it, how to take it, what you can expect while you're taking it, and any warnings about the medicine. The information provided here is general. So be sure...

  • What are the most important things you need to know about your medicines? Make sure you know about each of the medicines you take. This includes why you take it, how to take it, what you can expect while you're taking it, and any warnings about the medicine. The information provided here is general. So be sure...

  • Discusses common skin rashes that affect those 11 and younger. Covers chickenpox, diaper rash, prickly heat, and contact dermatitis. Offers home treatment tips for fever and itching. Includes interactive tool to help you decide when to call a doctor.

  • How can I prevent tetanus? You can help prevent tetanus by having all of the suggested tetanus shots ( immunizations). There are three different types of tetanus shots. Diphtheria, tetanus, and pertussis (DTaP). This vaccine is given in a series of five shots starting at age 2 months and ending at...

  • Lists common sexually transmitted infections, including chlamydia, genital herpes, gonorrhea, HIV, HPV (genital warts), syphilis, and trichomoniasis. Includes interactive tool to help you decide when to call a doctor. Covers safer sex. Offers prevention tips.

  • Guides through decision to take antiviral medicine for the flu. Explains the two types of antiviral medicines for the flu and who should take them. Covers benefits and risks. Includes an interactive tool to help you make your decision.

  • Guides you through the decision to get a flu vaccine. Provides info on the flu vaccine. Explains who should and should not get a flu vaccine. Covers benefits and risks. Includes interactive tool to help you make your decision.

  • All cases of tuberculosis (TB) are reported to the local or state health department, because the disease can spread to others and cause outbreaks. Major health authorities keep track of TB outbreaks and encourage early testing for people who are at risk for the disease. The CDC recommends TB testing for people who...

  • Here are some ways you can help comfort your child who has a respiratory illness (such as respiratory syncytial virus (RSV) infection or a cold): Ask your doctor if your child can take acetaminophen or ibuprofen to help relieve fever (if present). Be safe with medicines. Read and follow all instructions on the...

  • Is this topic for you? This topic is about many different types of food poisoning. You can also see the topics E. Coli Infection and Toxoplasmosis During Pregnancy. What is food poisoning? Food poisoning is an illness caused by eating foods that have harmful organisms in them. These harmful germs can...

  • Wash your hands often and prepare foods properly to reduce the risk of food poisoning . How to wash your hands The U.S. Centers for Disease Control and Prevention recommends the following steps for hand-washing: Wash your hands with running water, and apply soap. Rub your hands together to make a lather. Scrub...

  • There are things you can do while shopping to help prevent food poisoning. Put raw meat, poultry, eggs, fish, and shellfish in separate bags, and do not mix them with other food items. Do not buy meat or poultry that has a tear in the package or is leaking. Pick up your refrigerated and frozen items at the end of...

  • It is important to cook foods at a safe temperature to avoid food poisoning. The following picture shows you safe temperatures for a number of foods. Adapted from the U.S. Department of Agriculture, Food Safety and Inspection Service (2011). Safe Minimum Cooking Temperatures. Available online...

  • Storing food promptly and correctly can help prevent food poisoning. Set your refrigerator at or below 40 F (4 C) and your freezer at or below 0 F (-18 C). Refrigerate or freeze meat, poultry, eggs, fish, shellfish, ready-to-eat foods, and leftovers within 2 hours or sooner. If the temperature outdoors is above 90 F...

  • Food packaging labels provide information about when to use the food and how to store it. Reading food labels and following safety instructions will greatly reduce your chance of becoming ill with food poisoning. The following guidelines are included on a packaging label. Sell by: This tells the store...

  • You can help prevent food poisoning by taking precautions when serving food. Keep hot foods hot [ 140 F (60 C) or above] and cold foods cold [ 40 F (4 C) or below]. Never leave meat, poultry, eggs, fish, or shellfish (raw or cooked) at room temperature for more than 2 hours. If the temperature outdoors is...

  • Guides through decision to use antibiotics for a child's ear infection. Covers symptoms of an ear infection. Offers home treatment tips. Includes interactive tool to help you make your decision. This topic is only appropriate for children 6 months and older.

  • What is food-borne botulism? Food-borne botulism is a rare but serious type of food poisoning that can result in paralysis. It is caused by the Clostridium botulinum ( C. botulinum) bacterium. The bacteria produce a nerve toxin that can cause paralysis. Food-borne botulism can be fatal and is considered a medical...

  • What is campylobacteriosis? Campylobacteriosis is food poisoning caused by the campylobacter bacterium. It is one of the most common causes of diarrhea in the United States, affecting more than 2.4 million people every year. Campylobacteriosis occurs much more often in the summer months than in the winter months...

  • What is salmonellosis? Salmonellosis is a type of food poisoning caused by the Salmonella enterica bacterium. There are many different kinds of these bacteria. Salmonella serotype Typhimurium and Salmonella serotype Enteritidis are the most common types in the United States. Salmonellosis is more common in the summer...

  • What is staph food poisoning? Staph food poisoning is a type of food poisoning caused by infection with the Staphylococcus aureus ( S. aureus) bacterium. The bacteria multiply in foods and produce toxins especially if food is kept at room temperature. The toxins may be present in dangerous amounts in foods that have...

  • What is shigellosis? Shigellosis is a type of food poisoning caused by infection with the shigella bacterium. It is more common in summer than winter. Children ages 2 to 4 are most likely to get the condition. What causes shigellosis? Shigellosis is spread when the bacteria in feces (stool) or on soiled fingers are...

  • What is C. perfringens food poisoning? C. perfringens food poisoning is caused by infection with the Clostridium perfringens ( C. perfringens) bacterium. C. perfringens is found frequently in the intestines of humans and many animals and is present in soil and areas contaminated by human or animal feces...

  • What is cryptosporidiosis? Cryptosporidiosis is a diarrheal disease caused by the Cryptosporidium parvum parasite, also referred to as "Crypto." Crypto lives in the intestine of infected animals and humans and is passed through stool. What causes infection with cryptosporidiosis? Crypto is primarily transmitted by...

  • The human immunodeficiency virus (HIV) changes (mutates) often. Sometimes these changes make the virus resistant to a particular medicine or class of medicines, which means the medicine is no longer effective against the virus. When this happens, the medicine no longer controls virus growth (replication) or protects the...

  • Syphilis is described in terms of its four stages: primary, secondary, latent (hidden), and tertiary (late). Primary stage During the primary stage, a sore ( chancre) that is usually painless develops at the site where the bacteria entered the body. This commonly occurs within 3 weeks of exposure but can...

  • Medicines and vaccines are used to prevent infections and certain diseases ( opportunistic infections) that are more common in people with HIV. Primary prevention means preventing illness before it occurs. Immunizations (vaccines) are one kind of primary prevention. Medicines that kill or control the...

  • Pneumocystis is a fungus that can sometimes cause pneumonia in people who have AIDS. Pneumonia is an infection of the lungs. Pneumonia can make it hard to breathe and to get enough oxygen into the bloodstream. Symptoms often begin suddenly and may be similar to those of an upper respiratory infection, such as...

  • Antiretroviral therapy (ART) is the combination of several antiretroviral medicines used to slow the rate at which HIV makes copies of itself (multiplies) in the body. A combination of three or more antiretroviral medicines is more effective than using just one medicine (monotherapy) to treat HIV. The use of three or...

  • Opportunistic infections and diseases occur in people whose immune systems have been weakened. They usually do not occur in people who have healthy immune systems. When the immune system is weakened by a disease such as HIV infection, opportunistic diseases may cause serious, even life-threatening, illnesses...

  • Taking antiretroviral drugs for HIV will not cure your infection. But it may allow you to stay healthy for a long time. And treatment can help prevent spreading the infection to other people. Your willingness and ability to follow your antiretroviral therapy schedule exactly as prescribed is essential for successful...

  • Discusses smallpox, a contagious infection caused by the variola virus. Covers symptoms and how it's diagnosed. Discusses how it's spread. Discusses smallpox vaccine, including who should have it and who should not. Covers smallpox as a biological weapon.

  • The United States Preventive Services Task Force, U.S. Centers for Disease Control and Prevention, American Academy of Pediatrics, and American College of Obstetricians and Gynecologists recommend that all pregnant women be screened for human immunodeficiency virus (HIV) infection. This is because early detection and...

  • Guides you through the decision to treat a vaginal yeast infection yourself. Explains when you may need to see a doctor to diagnose a yeast infection. Discusses prescription and over-the-counter medicines. Includes interactive tool to help you decide.

  • Boric acid is a white, crystalline chemical substance that has antifungal and antiviral properties. It is used in various prescription pharmaceutical products and is also available without a prescription. Some experts now recommend vaginal boric acid capsules as a treatment option for vaginal yeast infections...

  • What is roseola? Roseola (roseola infantum) is a mild illness caused by a virus. It is generally harmless and is most common in children 6 months to 2 years of age. It is rare after age 4. What causes roseola? Roseola is caused by two common viruses. The viruses belong to the family of herpes viruses...

  • Discusses methicillin-resistant Staphylococcus aureus (MRSA), a type of staph bacteria. Covers how it is spread. Discusses antibiotic resistance of MRSA. Covers symptoms, diagnosis, and treatment.

  • What are vancomycin-resistant enterococci (VRE)? Vancomycin-resistant enterococci (VRE) are a type of bacteria called enterococci that have developed resistance to many antibiotics, especially vancomycin. Enterococci bacteria live in our intestines and on our skin, usually without causing problems. But if they...

  • Many people worry about getting a disease like hepatitis or HIV from an accidental needle stick. But it doesn't happen often. Most of the time, the person on whom the needle was used doesn't have hepatitis, HIV, or another infection that can be spread that way. When the person does have an infection that can be spread...

  • Discusses tetanus, also called lockjaw. Looks at cause by bacteria infection that makes a poison that causes severe muscle spasms. Looks at how bacteria enter the body through wound or cut. Covers vaccine shots (immunizations) to prevent tetanus.

  • What is bird flu? Bird flu is an infection caused by a certain kind of avian influenza virus. Although there are many kinds of bird flu, the most common kinds that concern health workers are H5N1 and H7N9 bird flu viruses. These viruses are found in wild birds. Most of the time, wild birds don't get sick from the...

  • Bacterial infections of the spine are rare but can include infection of: The discs (discitis). The spinal cord (usually an infection of the tissue covering the spinal cord, called an epidural abscess). One or more vertebrae (osteomyelitis). The facet joints, which may be the site of infectious arthritis. Bacteria...

  • A viral load test measures how much human immunodeficiency virus (HIV) is in the blood. Viral load is first measured when you are diagnosed with HIV infection. This first measurement serves as the baseline. Future viral load measurements will be compared with the baseline. Since viral load can vary from day to day, the...

  • A human papillomavirus (HPV) test is done to check for a high-risk HPV infection in women. HPV is a sexually transmitted infection (STI). An HPV test checks for the genetic material ( DNA) of the human papillomavirus. Like a Pap test, an HPV test is done on a sample of cells collected from the cervix. There are many...

  • What is mad cow disease, and does it infect people? Mad cow disease is a fatal disease that slowly destroys the brain and spinal cord ( central nervous system ) in cattle. It also is known as bovine spongiform encephalopathy, or BSE. People cannot get mad cow disease. But in rare cases they may get a human form of...

  • Briefly discusses scarlet fever, a term used for strep throat with a rash. Covers symptoms like red rash on chest, on abdomen, and in skin folds. Covers how it is treated. Also covers complications.

  • Hand-washing is more than just running water over your hands. Washing your hands with soap and water is the best way to prevent the spread of infections. It helps prevent diseases, such as colds, flu, and food poisoning. It's easy, it doesn't cost much, and it works. Wash your hands: Often, especially during cold and...

  • What are blood and body fluid precautions? Blood and body fluid precautions are recommendations designed to prevent the transmission of HIV, hepatitis B virus (HBV), hepatitis C virus (HCV), and other diseases while giving first aid or other health care that includes contact with body fluids or blood. These...

  • Many prescription and nonprescription medicines can cause vaginal symptoms. A few examples are: Antibiotics. Birth control pills. Hormone therapy. Chemotherapy for cancer. Vaginal sprays, douches, and spermicides. Vaginal symptoms may clear up on their own once you stop taking a medicine. A yeast infection can be...

  • The hepatitis A virus test is a blood test that shows if you have a hepatitis A infection now or had it in the past. The test looks for antibodies made by the body to fight the virus. They will be in your blood if you have a hepatitis A infection now or have had one in the past. Hepatitis A...

  • Hepatitis C virus (HCV) test is a blood test that looks for the genetic material ( RNA) of the virus that causes hepatitis or for the proteins ( antibodies) the body makes against HCV. These proteins will be present in your blood if you have a hepatitis C infection now or have had one in the past. Different tests are...

  • Lyme disease can go through several stages. It may cause different symptoms, depending on how long you have been infected and where in your body the infection has spread. Stage 1: Early localized Lyme disease (1 to 4 weeks) Early localized Lyme disease develops days to weeks after you become infected. You may have...

  • What is hand-foot-and-mouth disease? Hand-foot-and-mouth disease is an illness that causes sores or blisters in or on the mouth and on the hands, feet, and sometimes the buttocks and legs. They may be painful. The illness usually doesn't last more than a week or so. Hand-foot-and-mouth disease is common in children but...

  • Discusses anthrax, a disease caused by Bacillus anthracis bacteria. Covers symptoms based on the three types of infection. Discusses treatment with antibiotics and other medicines. Covers anthrax vaccine. Offers tips on reducing exposure risk.

  • If you have a normal heart, you have a low risk for endocarditis. But if you have a problem with your heart that affects normal blood flow through the heart, it is more likely that bacteria or fungi will attach to heart tissue. This puts you at a higher risk for endocarditis. If you have certain heart conditions...

  • Guides you through how to control itching when you or your child has chickenpox (varicella) rash. Includes home treatment with baths, over-the-counter medicines, and lotions. Covers avoiding scratching to prevent infection and scarring.

  • Disease-causing germs spread anytime large numbers of people are together or when people share items. Germs spread more easily during the colder months, because people spend a lot of time indoors around one another. Close and frequent contact with others makes it easier for germs to spread. Immunizations help protect...

  • What is rotavirus, and what causes it? Rotavirus is a virus that infects the intestinal tract. You can get rotavirus more than once, but the first infection is usually the worst. This infection causes stomach upset and diarrhea. Babies and very young children who have rotavirus infections need to be watched...

  • Guides you through the decision to take antiviral drugs for chronic hepatitis B. Covers treatment with interferons and nucleoside reverse transcriptase inhibitors. Lists side effects. Includes interactive tool to help you make your decision.

  • A postvaccination test for immunity to the hepatitis B virus (HBV) is recommended only if you: Have an impaired immune system. This can be caused by many things, such as infection with HIV or the use of medicines to prevent organ rejection. Are older than age 49. Received the hepatitis B vaccine in the buttock. (The...

  • What is West Nile virus? West Nile virus is a type of virus that is spread by mosquitoes. The infection it causes may be so mild that people don't even know they have it. But in rare cases, West Nile leads to severe illness that affects the brain or spinal cord. People older than 50 are at the highest risk for serious...

  • Rheumatic fever is a bacterial infection that can cause problems with the heart's aortic and mitral valves. Rheumatic fever is caused by certain strains of streptococcal bacteria. A strep throat infection that isn't properly treated can trigger rheumatic fever. Rheumatic fever can damage heart muscle and heart valves...

  • You can lower your chance of being bitten by an insect or spiderlike animal (arachnid) by using insect repellents. Mosquitoes, biting flies, and ticks can cause annoying bites and sometimes a serious disease. Mosquito bites can spread infections such as West Nile virus, a virus that causes swelling of the brain (...

  • What is SARS? Severe acute respiratory syndrome (SARS) is a respiratory illness that first infected people in parts of Asia, North America, and Europe in late 2002 and early 2003. SARS is caused by a type of coronavirus, which can cause mild to moderate upper respiratory illness, such as the common cold. This virus...

  • Guides through decision to take antibiotics for acute bronchitis. Explains when antibiotics are helpful. Covers risks of antibiotics. Includes interactive tool to help you make your decision.

  • What is listeriosis? Listeriosis is food poisoning caused by eating foods contaminated with the Listeria monocytogenes ( L. monocytogenes) bacterium. In pregnant women, the infection can result in miscarriage, premature delivery, serious infection of the newborn, or even stillbirth. Listeriosis affects mainly...

  • What are noroviruses? Noroviruses are also called Norwalk-like viruses and caliciviruses. Noroviruses cause gastroenteritis, food infection, food poisoning, and acute nonbacterial gastroenteritis. What causes infection with noroviruses? Noroviruses typically spread through contaminated water and foods, although they...

  • Toxoplasmosis is infection with the parasite Toxoplasma gondii. Most people who become infected don't have symptoms. This is because the immune system is usually able to fight the disease. Toxoplasmosis is dangerous to a pregnant woman and her...

  • Sexually transmitted infections (STIs) are some of the most widespread infections both in the United States and the world. STIs affect both men and women, and two-thirds of all STIs occur in people younger than 25. Exposure to an STI can occur any...

  • The American Association for the Study of Liver Disease has made recommendations for treating long-term (chronic) hepatitis B. These recommendations are based on the presence of hepatitis B antigens in your blood, the level of hepatitis B viral DNA ( HBV DNA) in your blood, and the level of the liver enzyme alanine...

  • What are marine toxins? Marine toxins are chemicals and bacteria that can contaminate certain types of seafood. Eating the seafood may result in food poisoning. The seafood may look, smell, and taste normal. There are five common types of marine toxins, and they all cause different symptoms. Food poisoning...

  • A balanced, nutritious diet during your pregnancy is important to maintain your health and nourish your fetus. When making your food choices, you generally are able to eat the foods you usually eat. But because some types of food poisoning pose a greater risk to you and your fetus, you should take a few extra...

  • What is Vibrio vulnificus food poisoning? Vibrio vulnificus food poisoning is caused by Vibrio vulnificus, a bacterium that lives in warm seawater. The condition is rare. What causes Vibrio vulnificus food poisoning? Vibrio vulnificus food poisoning occurs when you eat seafood infected with the bacteria or you...

  • What is healthcare-associated pneumonia? Healthcare-associated pneumonia (nosocomial pneumonia) is pneumonia that you get when you are in a hospital or nursing home. Experts generally consider it a more serious illness than pneumonia that people get in daily life (community-associated pneumonia). This is because the...

  • What are Legionnaires' disease and Pontiac fever? Legionnaires' disease is a type of pneumonia. It is caused by bacteria called Legionella pneumophila. The bacteria got its name in 1976, when a group of people attending an American Legion convention became infected. Although it was present before 1976, Legionnaires'...

  • High blood sugar from diabetes can affect the body's immune system, impairing the ability of white blood cells to come to the site of an infection, stay in the infected area, and kill microorganisms. Because of the buildup of plaque in blood vessels associated with diabetes, areas of infection may receive a poor blood...

  • A few people with HIV are described as nonprogressors. These people have HIV that does not progress to more severe symptoms or disease, but they can still spread HIV. Most nonprogressors: Have lived with the infection for 10 to 15 years and remained healthy. Do not have declining CD4+ cell counts...

  • Guides through decision to have your child get the HPV vaccine. Explains the vaccination process and includes tips on how to talk to your child about HPV. Covers benefits and risks. Includes an interactive tool to help you make your decision.

  • What is valley fever? Valley fever is a disease caused by a fungus that gets into your body through your lungs. It can make you feel like you have a cold or the flu and may cause a rash. Most people get better without treatment. But if your body's natural defense system ( immune system) is weak, valley fever can be...

  • Looks at causes and symptoms of group B streptococcal infections in newborns. Explains what group B strep is. Covers how and why it is treated. Includes treatment for mothers and newborns.

  • Weight loss in people with HIV has many possible causes. If you lose weight fast, it may be because you have another infection along with HIV. This type of illness is called an opportunistic infection. Gradual weight loss may be due to problems with nutrition. You may lose weight if you can't eat enough food or if your...

  • Feeling tired is common if you have HIV, especially if you have had the virus for many years. Being severely tired can affect your ability to work, take care of yourself, and enjoy your life. There can be many reasons why you are tired. It is important that you and your doctor try to find the cause. Many of the things...

  • What is vaginitis? Vaginitis is infection or inflammation of the vagina. It can cause itching and burning, a change in vaginal discharge, and sometimes pain during sex. What causes vaginitis? Vaginitis may be caused by bacteria, yeast, or other organisms. Bath products, douches, and spermicides also can...

  • What are colds? Everyone gets a cold from time to time. Children get more colds than adults. Colds usually last 1 to 2 weeks. You can catch a cold at any time of year, but they are more common in late winter and early spring. There is no cure for a cold. Antibiotics will not cure a cold. If you catch a cold...

  • Guides through decision to be tested for hepatitis B. Explains hepatitis B and discusses causes and lifestyles that put you at higher risk. Covers benefits and risks. Includes an interactive tool to help you make your decision.

  • Guides you through the decision to take antibiotics to treat sinusitis. Explains causes of sinusitis and how well antibiotics work. Lists risks. Discusses other treatment for sinus infection. Includes interactive tool to help you decide.

  • Guides readers through the decision to take antibiotics for sore throat. Explains the causes of sore throat and that most sore throats are caused by virus. Explains that antibiotics only work for sore throat caused by bacterial infections.

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