Sickle cell test
Sickledex; Hgb S test
The sickle cell test looks for the abnormal hemoglobin in the blood that causes the disease sickle cell anemia .
Hemoglobin
Hemoglobin is a protein in red blood cells that carries oxygen. The hemoglobin test measures how much hemoglobin is in your blood.
Sickle cell anemia
Sickle cell anemia is a disease passed down through families. The red blood cells that are normally shaped like a disc take on a sickle or crescent ...
How the Test is Performed
A blood sample is needed.
Blood sample
Venipuncture is the collection of blood from a vein. It is most often done for laboratory testing.
How the Test will Feel
When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a bruise. This soon goes away.
Why the Test is Performed
This test is done to tell if a person has abnormal hemoglobin that causes sickle cell disease and sickle cell trait. Hemoglobin is a protein in red blood cells that carries oxygen.
In sickle cell disease, a person has two abnormal hemoglobin S genes. A person with sickle cell trait has only one of these abnormal genes and no symptoms, or only mild ones.
This test does not tell the difference between these two conditions. Another test, called hemoglobin electrophoresis , will be done to tell which condition someone has.
Hemoglobin electrophoresis
Hemoglobin is a protein that carries oxygen in the blood. Hemoglobin electrophoresis measures the levels of the different types of this protein in t...
Normal Results
A normal test result is called a negative result.
Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your health care provider about the meaning of your specific test results.
What Abnormal Results Mean
An abnormal test result indicates the person might have one of these:
- Sickle cell anemia
- Sickle cell trait
Iron deficiency or blood transfusions within the past 3 months can cause a "false negative" result. This means the person might have the abnormal hemoglobin for sickle cell, but these other factors are making their test results appear negative (normal).
Risks
Veins and arteries vary in size from one person to another, and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight, but may include:
- Excessive bleeding
- Fainting or feeling lightheaded
- Hematoma (blood buildup under the skin)
- Infection (a slight risk any time the skin is broken)
References
Steinberg MH. Sickle cell disease and associated hemoglobinopathies. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 163.
Wetzler M, Cornett PA. Hematology. In: Bope ET, Kellerman RD, eds. Conn's Current Therapy 2016 . Philadelphia, PA: Elsevier Saunders; 2016:chap 12.
-
Red blood cells, sickle cell - illustration
Sickle cell anemia is an inherited blood disease in which the red blood cells produce abnormal pigment (hemoglobin). The abnormal hemoglobin causes deformity of the red blood cells into crescent or sickle-shapes, as seen in this photomicrograph.
Red blood cells, sickle cell
illustration
-
Red blood cells, multiple sickle cells - illustration
Sickle cell anemia is an inherited disorder in which abnormal hemoglobin (the red pigment inside red blood cells) is produced. The abnormal hemoglobin causes red blood cells to assume a sickle shape, like the ones seen in this photomicrograph.
Red blood cells, multiple sickle cells
illustration
-
Red blood cells, sickle cells - illustration
These crescent or sickle-shaped red blood cells (RBCs) are present with Sickle cell anemia, and stand out clearly against the normal round RBCs. These abnormally shaped cells may become entangled and block blood flow in the small blood vessels (capillaries).
Red blood cells, sickle cells
illustration
-
Red blood cells, sickle and pappenheimer - illustration
This photomicrograph of red blood cells (RBCs) shows both sickle-shaped and Pappenheimer bodies.
Red blood cells, sickle and pappenheimer
illustration
-
Red blood cells, sickle cell - illustration
Sickle cell anemia is an inherited blood disease in which the red blood cells produce abnormal pigment (hemoglobin). The abnormal hemoglobin causes deformity of the red blood cells into crescent or sickle-shapes, as seen in this photomicrograph.
Red blood cells, sickle cell
illustration
-
Red blood cells, multiple sickle cells - illustration
Sickle cell anemia is an inherited disorder in which abnormal hemoglobin (the red pigment inside red blood cells) is produced. The abnormal hemoglobin causes red blood cells to assume a sickle shape, like the ones seen in this photomicrograph.
Red blood cells, multiple sickle cells
illustration
-
Red blood cells, sickle cells - illustration
These crescent or sickle-shaped red blood cells (RBCs) are present with Sickle cell anemia, and stand out clearly against the normal round RBCs. These abnormally shaped cells may become entangled and block blood flow in the small blood vessels (capillaries).
Red blood cells, sickle cells
illustration
-
Red blood cells, sickle and pappenheimer - illustration
This photomicrograph of red blood cells (RBCs) shows both sickle-shaped and Pappenheimer bodies.
Red blood cells, sickle and pappenheimer
illustration
-
Sickle cell disease
(In-Depth)
Review Date: 2/11/2016
Reviewed By: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.