Sickle cell anemia is a disease passed down through families in which red blood cells form an abnormal sickle or crescent shape. Red blood cells carry oxygen to the body and are normally shaped like a disc.
Sickle cell anemia is caused by an abnormal type of hemoglobin called hemoglobin S. Hemoglobin is a protein inside red blood cells that carries oxygen.
Hemoglobin S changes the shape of red blood cells. The red blood cells become shaped like crescents or sickles.
The fragile, sickle-shaped cells deliver less oxygen to the body's tissues.
They can also get stuck more easily in small blood vessels, as well as break into pieces that can interrupt healthy blood flow. These problems decrease the amount of oxygen flowing to body tissues even more.
Sickle cell anemia is inherited from both parents. If you inherit the sickle cell gene from only one parent, you will have sickle cell trait. People with sickle cell trait do not have the symptoms of sickle cell anemia.
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.
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 becomes more severe, symptoms may include:
The goal of treatment is to manage and control symptoms, and to limit the number of crises. Patients with sickle cell disease need ongoing treatment, even when they are not having a painful crisis. It is best to receive care from health care providers and clinics that take care of many patients with sickle cell anemia.
Folic acid supplements should be taken. Folic acid is needed to make new red blood cells.
Treatment for a sickle cell crisis includes:
Blood transfusions (may also be given regularly to prevent stroke)
Plenty of fluids
Other treatments for sickle cell anemia may include:
Hydroxyurea (Hydrea), a medicine that may help reduce the number of pain episodes (including chest pain and difficulty breathing) in some people
Antibiotics to prevent bacterial infections, which are common in children with sickle cell disease
Treatments that may be needed to manage complications of sickle cell anemia include:
Treatment for overuse or abuse of narcotic pain medicines
Wound care for leg ulcers
Bone marrow or stem cell transplants can cure sickle cell anemia. However, they are currently not an option for most patients. Sickle cell anemia patients are often unable to find well-matched stem cell donors.
People with sickle cell disease must reduce their risk of infections. This includes receiving certain vaccinations, including:
Joining a support group where members share common experiences can relieve the stress related to caring for someone with a chronic disease. See: Sickle cell anemia - support group
In the past, sickle cell patients often died 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.
Calling your health care provider
Call your health care provider if you have:
Any symptoms of infection (fever, body aches, headache, fatigue)
Painful and long-term erection (in men)
Rees DC, Williams TN, Gladwin MT. Sickle-cell disease. Lancet. 2010;376(9757):2018-2031.
Lee MT, Piomelli S, Granger S, et al. Stroke prevention trial in sickle cell anemia (STOP): extended follow-up and final results. Blood. 2006;108:847-852.
Brawley OW, Cornelius LJ, Edwards LR, Gamble VN, Green BL, Inturrisi C, et al. National Institutes of Health consensus development conference statement: hydroxyurea treatment for sickle cell disease. Ann Intern Med. 2008;148:932-938.
Geller AK, O'Connor MK. The sickle cell crisis: a dilemma in pain relief. Mayo Clin Proc. 2008;83:320-323.
Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.