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.
You could be out for a run or drifting off to sleep when it happens: The muscles of your calf or foot suddenly become hard, tight, and extremely painful. You are having a muscle cramp.
Sometimes called charley horses -- particularly when they are in the calf muscles -- cramps are caused by muscle spasms, involuntary contractions of one or more muscles. In addition to the foot and calf muscles, other muscles prone to spasms include the front and back of the thigh, the hands, arms, abdomen, and muscles...
Sickle cell disease causes red blood cells to form into a crescent shape, like a sickle. 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 causes the symptoms of sickle cell disease.
Children are born with sickle cell disease; it is not contagious. It occurs when a child inherits two sickle hemoglobin genes, one from each parent. About 2,000 babies are born with sickle cell disease each year in the United States. People who inherit only one sickle hemoglobin gene are carriers (sickle cell trait) and do not have anemia or painful sickle cell crises. They may, though, have a slightly higher incidence of certain conditions such as blood in the urine or urinary tract infections. About 2 million Americans have sickle cell trait.