People with sickle cell disease (or anemia) have an abnormal form of blood cell (Hemoglobin S) which causes the red blood cells to be curved into crescent or “sickle” shape and not the normal, round shape.  Round blood cells pass through blood vessels easily, carrying oxygen throughout your body. Sickle-shaped blood cells can get stuck, block blood vessels and prevent oxygen from getting through. Symptoms of sickle cell disease are very painful and can cause long term damage to organs, muscles and bones. Painful episodes due to blocked blood vessels can cause pain in the hands, feet, belly, back or chest. Sickle cell disease may also cause numerous infections and anemia leading to weakness and fatigue.