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Medical Author:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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In this Article

• What is sickle cell anemia?
• How is sickle cell anemia inherited?
• What conditions promote the sickling (distortion) of the red blood cells in sickle cell anemia?
• How is sickle cell anemia diagnosed?
• What are the symptoms and treatments of sickle cell anemia?
• What is the outlook (prognosis) for patients with sickle cell anemia?
• Sickle Cell Anemia At A Glance
• Patient Comments: Sickle Cell Disease (Anemia) - Diagnosis
• Patient Comments: Sickle Cell Disease (Sickle Cell Anemia) - Experience
• Find a local Hematologist in your town
• Sickle Cell Index

Sickling of the red blood cells in patients with sickle cell anemia results in cells of abnormal shape and flexibility. The sickling is promoted by conditions which are associated with low oxygen levels, increased acidity, or low volume (dehydration) of the blood. These conditions can occur as a result of injury to the body's tissues, dehydrating states, or anesthesia.

Even certain organs are predisposed to lower oxygen levels or acidity, such as when blood moves slowly through the spleen, liver, or kidney. Also, organs with particularly high metabolism rates (such as the brain, muscles, and the placenta in a pregnant woman with sickle cell anemia) promote sickling by extracting more oxygen from the blood. These conditions make these organs susceptible to injury from sickle cell anemia.

Sickle cell anemia is suggested when the abnormal sickle-shaped cells in the blood are identified under a microscope. Testing is typically performed on a smear of blood using a special low-oxygen preparation. This is referred to as a sickle prep. Other prep tests can also be used to detect the abnormal hemoglobin S, including solubility tests performed on tubes of blood solutions. The disease can be confirmed by specifically quantifying the types of hemoglobin present using a hemoglobin electrophoresis test.

Prenatal diagnosis (before birth) of sickle cell anemia is possible using amniocentesis or chorionic villus sampling. The sample obtained is then tested for DNA analysis of the fetal cells.

The hemoglobin electrophoresis test precisely identifies the hemoglobins in the blood by separating them. The separation of the different hemoglobins is possible because of the unique electrical charges they each have on their protein surfaces, causing them each to move characteristically in an electrical field as tested in the laboratory.