Anemia is a condition in which a person doesn't have enough red blood cells. With fewer red blood cells, your blood isn't able to carry enough oxygen to the cells in your body. This can cause symptoms such as weakness, skin that is more pale than usual, and general tiredness (fatigue).

Different types of anemia are caused by:

• Blood loss, such as heavy bleeding during periods or bleeding inside your body from ulcers or another problem.
• Too many red blood cells being destroyed, such as from a disease (like thalassemia or sickle cell disease) or from cancer treatments (like chemotherapy).
• Not enough red blood cells being made by your body, such as if what you eat doesn't have enough nutrients, or if you are pregnant, or you have a disease (like chronic kidney disease, diabetes, or cancer).

Each type of anemia is treated differently.