Bacterial Vaginosis Tests
Tests for bacterial vaginosis take samples of fluid from the vagina. The samples are looked at under a microscope to see if they show signs of infection.
Bacterial vaginosis can happen when certain types of bacteria that are normally in the vagina overgrow. It doesn't always cause symptoms. But the most common symptom is an increase in vaginal discharge. The discharge often has a fishy odor.
Tests for bacterial vaginosis include:
- Wet mount. A sample of vaginal discharge is checked for bacteria, white blood cells, and unusual cells called clue cells. If clue cells are found, it means you may have bacterial vaginosis.
- Whiff test. A sample of discharge is checked to see if a strong fishy odor is created when a special solution is added. A fishy odor usually means you have bacterial vaginosis.
- Vaginal pH. The pH of a sample of vaginal discharge is measured. Bacterial vaginosis often causes a pH that is higher than normal.
- DNA test. A sample of vaginal discharge is tested for the genetic material, or DNA, of this bacteria.
Why It Is Done
Tests for bacterial vaginosis are done to help find the cause of symptoms such as abnormal vaginal discharge, irritation, or pain.
How To Prepare
Your doctor may ask you not to douche, have sex, or use vaginal medicines for 24 hours before this test.
How It Is Done
You will take off your clothes below the waist. You'll have a gown to drape around your waist. You will then lie on your back on an examination table with your feet supported by footrests. This is similar to having a pelvic examination or Pap test.
Your doctor will place a speculum into your vagina. It opens the vagina a little bit. This allows your doctor to see the inside of the vagina and the cervix.
Samples of fluid inside the vagina are then collected with a swab.
How It Feels
You may feel some discomfort when the speculum is put in, especially if your vagina is irritated and tender.
There is no abnormal discharge in the vagina.
A wet mount does not show clue cells or large numbers of bacteria that cause bacterial vaginosis.
Adding a special solution to a sample of the discharge doesn't cause a fishy odor.
Vaginal pH is in the normal range.
There is a thin, grayish white discharge in the vagina.
A wet mount shows clue cells or large numbers of the types of bacteria that cause bacterial vaginosis, or both.
Adding a special solution to a sample of the discharge causes a fishy odor.
Vaginal pH is higher than normal.
Current as of: August 2, 2022
Author: Healthwise Staff
Medical Review:Sarah Marshall MD - Family Medicine & Martin J. Gabica MD - Family Medicine & Kathleen Romito MD - Family Medicine & Devika Singh MD, MPH - Infectious Disease