When they become oxidized again the hemoglobin returns to its former liquid state. They both carry the same amounts of oxygen but when they lack oxygen, Hb S becomes, unlike Hb A, hard and inflexible. When they travel through narrow veins or arteries, Hb S can become stuck and block off blood flow to and from the affected area. "Hb S inside the red blood cell come together and stick to each other in a process called polymerization and this forms the rigid, sickle-like shape of the affected blood cell."4 But once these blood cells are exposed to oxygen, the Hb S in the red blood cell will dissolve and resume its normal activities, however the blood cell has been damaged and after several reversals the blood cells become irreversibly sickled and they are permanently damaged. These damaged blood cells are destroyed. Because of this, the life of a red blood cell with Hb S is greatly reduced, "normal blood cells live for about 120 days while those with the abnormal hemoglobin lives for less than half of that time."5 The body now has a much lower number of blood cells because new blood cells cannot be made fast enough. This condition produces anemia, which is a deficiency of hemoglobin. .

             Symptoms for Sickle Cell Anemia:.

             There are several signs or symptoms that can indicate sickle cell anemia. The severity and characteristics of the symptoms may differ between age groups and individuals. Some people may never become seriously ill and others may only have some of the symptoms. .

             Painful crisis or episodes are very common to a person with sickle cell disease. Most of the pain comes from the blockage of small blood vessels in the body. When the vessels are blocked oxygen cannot get through to supply the other parts of the body. "If an area of the body is deprived of its oxygen supply, the body emits chemicals that cause pain. Tissue damage is soon to follow and when the tissue is damaged the area is inflamed which also causes pain.