Iron deficiency anemia means that your body doesn't have the iron it needs to make enough red blood cells. Red blood cells carry oxygen around your body. With fewer red blood cells, your blood isn't able to carry enough oxygen to the cells in your body.
Iron deficiency anemia can happen if you don't get enough iron in your diet or if your body isn't absorbing enough iron. And it can happen if you have prolonged bleeding, such as heavy menstrual bleeding or bleeding from stomach ulcers.
This type of anemia doesn't always cause symptoms. But it can make you feel weak and tired or dizzy. Your doctor will probably have you take iron pills and eat healthy, iron-rich foods.