Join the Fight Against Sickle Cell Disease! About 100,000 people in the United States have sickle cell disease. Most are of African descent. The disease causes red blood cells to harden and form a C-shape (like a sickle). When hardened, the cells can get caught in blood vessels and cause serious complications for patients. These complications can include severe pain, respiratory conditions, organ failure, and even stroke. There is no widely used cure for sickle cell disease. However, the Red Cross supports one of the most critical sickle cell treatments of all – blood transfusions. For many patients, a close blood type match is essential and is found in donors of the same race or similar ethnicity. Sickle cell disease is an inherited blood disorder that affects red blood cells. People with sickle cell disease have red blood cells that contain mostly hemoglobin S, an abnormal type of hemoglobin. Sometimes these red blood cells become sickle-shaped (crescent shaped) and have difficulty passing through small blood vessels. When sickle-shaped cells block small blood vessels, less blood can reach that part of the body. Tissue that does not receive a normal blood flow eventually becomes damaged. This is what causes the complications of sickle cell disease. There is currently no universal cure for sickle cell disease.