Anemia (uh-NEE-me-eh) is a condition in which your blood has a lower than normal number of red blood cells. This condition also can occur if your red blood cells don’t contain enough hemoglobin (HEE-muh-glow-bin). Hemoglobin is an iron-rich protein that gives blood its red color. This protein helps red blood cells carry oxygen from the lungs to the rest of the body.
If you have anemia, your body doesn’t get enough oxygen-rich blood. As a result, you may feel tired and have other symptoms. With severe or long-lasting anemia, the lack of oxygen in the blood can damage the heart, brain, and other organs of the body. Very severe anemia may even cause death.
Red blood cells are disc-shaped and look like doughnuts without holes in the center. They carry oxygen and remove carbon dioxide (a waste product) from your body. These cells are made in the bone marrow—a sponge-like tissue inside the bones. Red blood cells live for about 120 days in the bloodstream and then die.
White blood cells and platelets (PLATE-lets) also are made in the bone marrow. White blood cells help fight infection. Platelets stick together to seal small cuts or breaks on the blood vessel walls and stop bleeding. With some types of anemia, you may have low numbers of all three types of blood cells.
Anemia has three main causes:
blood loss, lack of red blood cell production, or high rates of red blood cell destruction. These causes may be due to a number of diseases, conditions, or other factors.