Anemia, uh NEE mee uh, is a condition in which the number of healthy red blood cells falls below normal. Red blood cells pick up oxygen in the lungs and carry it to tissues throughout the body. There, the oxygen is combined with food to release energy. In an anemic person, the blood cannot provide the tissues with enough oxygen. Thus, the person feels weak or tired. Other symptoms are dizziness, headaches, pale or cool skin, rapid heartbeat, and shortness of breath.