Sickle cell disease is an inherited blood disorder that affects nearly 100,000 people in the United States. Red blood cells contain hemoglobin, a protein that carries oxygen in the blood. Normal red blood cells are round and flexible, which enables them to travel through small blood vessels to deliver oxygen to all parts of the body.
Sickle cell disease causes red blood cells to form into a crescent shape. The sickle-shaped red blood cells break apart easily causing anemia. Sickle red blood cells live only 10-20 days instead of the normal 120 days. The damaged sickle red blood cells also clump together and stick to the walls of blood vessels, blocking blood flow. This can cause severe pain and permanent damage to the brain, heart, lungs, kidneys, liver, bones, and spleen. Severe pain is an emergency called acute sickle cell crisis. A person may not know what brought on the pain, but infection and dehydration are common triggers.
Sickle cell disease is most common in Africans and African-Americans. It is also found in other ethnic and racial groups, including people from South and Central America, the Caribbean, Mediterranean countries, and India.
What Causes Sickle Cell Disease?
Sickle cell disease is caused by a genetic abnormality in the gene for hemoglobin, which results in the production of sickle hemoglobin. When oxygen is released from sickle hemoglobin, it sticks together and forms long rods, which damage and change the shape of the red blood cell. The sickle red blood cells cause the symptoms of sickle cell disease.
Symptoms usually do not occur until after age 4 months. Almost all patients with sickle cell anemia have painful episodes (called crises), which can last from hours to days. These crises can cause pain in the bones of the back, the long bones, and the chest. Some patients have one episode every few years. Others have many episodes per year. The crises can be severe enough to require a hospital stay. When the anemia...