What is sickle cell disease?

Sickle cell disease is an inherited (passed from parent to child) disorder that affects the body’s red blood cells. In this disease, defective hemoglobin (a substance that carries oxygen in the blood) causes the red blood cells to change shape (into a sickle) when oxygen is released to tissues.

Normal red blood cells are round and are able to move through small blood vessels in the body to deliver oxygen. In sickle cell disease, a chemical change in hemoglobin causes the substance to form long rods in the red blood cell as the hemoglobin releases oxygen. These rigid rods change the shape of the red blood cell into a sickle shape.

The disease gets its name because the faulty blood cells are shaped like sickles used to cut wheat. When the deformed cells go through blood vessels, they become stiff, distorted, clog the blood flow, and can break apart.

Individuals with sickle cell disease have hemoglobin "S," which may be homogenous or also be in combination with other abnormal hemoglobins (Hemoglobin C; Beta thalassemia trait or other rare Hemoglobin variants). Others without this disease have hemoglobin "A", which is the normal adult hemoglobin.

Sickle cell disease is found most often in African-Americans and Africans. However, other ethnic groups also can have sickle cell disease. In many states, the law requires newborn babies to be tested for sickle cell disease, regardless of ethnic background.

What causes sickle cell disease?

A chemical change in hemoglobin causes the substance to form long rods in the red blood cell as the hemoglobin releases oxygen. These rigid rods change the shape of the red blood cell into a sickle shape.

Sickle cell disease is not contagious. Children are born with sickle cell hemoglobin, which they inherit from their parents. Individuals might be carriers who have the sickle cell trait or might actually have sickle cell disease. People who inherit only 1 sickle cell gene are carriers, but people who inherit 2 sickle cell genes have sickle cell disease.

What are the symptoms of sickle cell disease?

Symptoms of sickle cell disease include:

  • Fatigue.
  • Pain.
  • Anemia.
  • Swelling and inflammation of the joints.
  • Blood blockage in the spleen or liver.

What are the medical problems of sickle cell disease?

Medical problems associated with sickle cell disease include:

  • Respiratory illness known as acute chest syndrome.
  • Pain episodes.
  • Stroke.
  • Priapism (a persistent, usually painful, erection that lasts for more than four hours).
  • Infections.

Sickle cell disease can also cause damage to bones and many organs, including the heart, lungs, kidneys, and spleen.

Last reviewed by a Cleveland Clinic medical professional on 10/24/2016.

References

  • National Library of Medicine. Genetics Home Reference. Sickle Cell Disease. Accessed 11/10/2016.
  • National Marrow Donor Program. Sickle Cell Disease Accessed 11/10/2016
  • Williams-Johnson J, Williams E. Sickle Cell Disease and Hereditary Hemolytic Anemias. In: Tintinalli JE, Stapczynski J, Ma O, Yealy DM, Meckler GD, Cline DM. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 8e. New York, NY: McGraw-Hill; 2016. accessmedicine.mhmedical.com Accessed 11/10/ 2016.

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