Sickle cell anemia is a disease passed down through families in which red blood cells form an abnormal crescent shape. (Red blood cells are normally shaped like a disc.)
Hemoglobin is a protein inside red blood cells that carries oxygen. Sickle cell anemia is caused by an abnormal type of hemoglobin called hemoglobin S. Hemoglobin S distorts the shape of red blood cells, especially when exposed to low oxygen levels.
The distorted red blood cells are shaped like crescents or sickles. These fragile, sickle-shaped cells deliver less oxygen to the body's tissues. They can also clog more easily in small blood vessels, and break into pieces that disrupt healthy blood flow.
Sickle cell anemia is inherited from both parents. Sickle cell disease is much more common in people of African and Mediterranean descent. It is also seen in people from South and Central America, the Caribbean, and the Middle East.
Someone who inherits the hemoglobin S gene from one parent and normal hemoglobin (A) from the other parent will have sickle cell trait. People with sickle cell trait do not have the symptoms of true sickle cell anemia.
Symptoms usually don't occur until after age 4 months.
Almost all patients with sickle cell anemia have painful episodes (crises), which can last from hours to days. These crises can affect 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.
Common symptoms include:
Other symptoms include:
Tests commonly performed to diagnose and monitor patients with sickle cell anemia include:
Other tests may include:
Patients with sickle cell disease need ongoing treatment, even when they are not having a painful crisis. They should take supplements of folic acid (essential for producing red blood cells) because red blood cells are turned over so quickly.
The purpose of treatment is to manage and control symptoms, and to limit the frequency of crises.
During a sickle cell crisis, you may need certain treatments. Painful episodes are treated with pain medicines and by drinking plenty of fluids. It is important to treat the pain. Non-narcotic medications may be effective, but some patients will need large doses of narcotics.
Hydroxyurea (Hydrea) is a drug some patients use to reduce the number of pain episodes (including chest pain and difficulty breathing). It does not work for everyone.
Antibiotics and vaccines are given to prevent bacterial infections, which are common in children with sickle cell disease.
Blood transfusions are used to treat a sickle cell crisis. They may also be used on a regular basis to help prevent strokes.
Other treatments for complications may include:
Bone marrow or stem cell transplants can cure sickle cell anemia. However, transplants have many risks, including infection, rejection, and graft-vs-host disease. Therefore, they are currently not an option for most patients. Also, sickle cell anemia patients are often unable to find well-matched donors.
Sickle cell anemia can cause great stress to the patient and family members. Joining a support group where members share common experiences and problems can relieve this stress.
See: Sickle cell anemia - support group
In the past, sickle cell patients often died from organ failure between ages 20 and 40. Thanks to a better understanding and management of the disease, today, patients can live into their 50s or beyond.
Causes of death include organ failure and infection. Some people with the disease experience minor, brief, infrequent episodes. Others experience severe, long-term, frequent episodes with many complications.
Call your health care provider if you have:
Sickle cell anemia can only occur when two people who carry sickle cell trait have a child together. Genetic counseling is recommended for all carriers of sickle cell trait. About 1 in 12 African Americans has sickle cell trait. It is possible to diagnose sickle cell anemia during pregnancy.
You can prevent sickling of red blood cells by:
Have physical exams every 3 - 6 months to ensure that you are getting enough nutrition and activity, and that you are receiving the proper vaccinations. Regular eye exams are also recommended.
Parents should encourage children with sickle cell anemia to lead normal lives.
To reduce sickle cell crises, take the following precautions:
Be aware of the effects that chronic, life-threatening illnesses can have on siblings, marriages, parents, and the child.
Anemia - sickle cell; Hemoglobin SS disease (Hb SS); Sickle cell disease