Sickle cell disease (SCD) is a blood disorder. Some red blood cells (RBCs) change to a sickle (crescent moon) shape. The sickle RBCs can block blood flow in blood vessels. This will slow or stop the flow of blood and oxygen to tissues and organs.
The body also destroys the sickle RBCs. Low levels of RBCs is a condition called anemia. This makes it harder for the body to get the oxygen it needs.
SCD can range from mild to severe and life-threatening.
Red Blood Cells: Normal and Sickle
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A defect in the genes causes SDC. This gene causes a problem with a part of the RBC called hemoglobin.
Parents pass the defect to their children. A person can only develop SCD if they get the defective gene from both parents.
If a person gets one defective gene, they will not have SCD. But, they can pass this gene on to their children.
Sickle cell disease is most common in people who are Black or have with African ancestry.
Other backgrounds with high risk are Hispanic, Asian Indian, Middle Eastern, and southern European.
Symptoms may be noticed as early as 6 months old. They are different in everyone depending on where problems are in the body. The most common are:
Signs of acute chest syndrome (ACS) are:
SDC crisis may cause:
SCD may cause other serious problems. Examples are a stroke, or painful erections lasting 4 hours or more. These problems need care right away.
All newborns have a screening test at birth. Blood tests will show the sickle shaped RBCs and other problems that indicate SCD. The doctor may also do a physical exam and genetic testing.
The goal is to ease symptoms and lower the risk of health problems. If pain crises or problems from SCD are severe, hospital care will be needed.
Treatment options may include:
More treatments may be needed. It depends on how SCD affects the body.
There is no way to prevent sickle cell disease. If planning a family, people at high risk may consider genetic testing.
American Sickle Cell Anemia Association
Sickle Cell Information Center
About Kids Health—The Hospital for Sick Children
Sickle Cell Foundation of Alberta
Onimoe G, Rotz S. Sickle cell disease: A primary care update. Cleve Clin J Med. 2020;87(1):19-27.
Sickle cell disease. Family Doctor—American Academy of Family Physicians website. Available at: https://familydoctor.org/condition/sickle-cell-disease. Accessed July 22, 2021.
Sickle cell disease. Kids Health—Nemours Foundation website. Available at:
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Accessed July 22, 2021.
Sickle cell disease. National Heart, Lung, and Blood Institute website. Available at: https://www.nhlbi.nih.gov/health-topics/sickle-cell-disease. Accessed July 22, 2021.
Sickle cell disease (SCD). Centers for Disease Control and Prevention website. Available at: https://www.cdc.gov/ncbddd/sicklecell/index.html. Accessed July 23, 2021.
Sickle cell disease in adults and adolescents. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/sickle-cell-disease-in-adults-and-adolescents . Accessed July 23, 2021.
Sickle cell disease in infants and children. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/sickle-cell-disease-in-infants-and-children . Accessed July 23, 2021.
Last reviewed July 2021 by
EBSCO Medical Review Board
Michael Fucci, DO, FACC
Last Updated: 7/23/2021