What is Sickle Cell Disease?

Sickle cell anemia is an inherited disease that affects red blood cells with an abnormal version of hemoglobin, the protein that carries oxygen throughout the body. The altered hemoglobin is known as hemoglobin S, or sickle hemoglobin, because it causes normally oval-shaped red blood cells to assume a sickle shape.

What causes sickle cell anemia?

Sickle cell anemia is caused by a mutation of the HBB gene that produces hemoglobin protein. People with sickle cell anemia have inherited two abnormal copies of the gene, one from each parent. People with a faulty gene from only one parent do not develop sickle cell anemia, but instead, a condition called sickle cell trait.

How does sickle cell anemia affect the body?

Red blood cells with healthy hemoglobin have a disc-shaped structure. This makes them flexible,  allowing them to carry oxygen throughout the bloodstream to organs and tissue.

Red blood cells with sickle hemoglobin become rigid, making it difficult for them to get through smaller blood vessels. This prevents or slows blood flow.

The result is oxygen being unable to reach places it’s supposed to, causing inflammation and episodes of sudden and severe pain, known as pain crises. Pain usually disappears between the crises in children with sickle cell anemia, but it can persist in adolescents and adults.

Another consequence of poor oxygen delivery is damage to major organs, including the brain, eyes, lungs, liver, heart, spleen, and kidneys.

Red blood cells with sickle hemoglobin usually die much quicker than healthy cells. Their typical lifespan is 10 to 20 days, versus 90 to 120 for normal cells.

Although the body is always working to replace red blood cells that die, with sickle cell, it can’t replace them fast enough. This leads to a lower than normal level of the cells, causing anemia, or tiredness and weakness.

People with sickle cell anemia can also have painfully swollen hands and feet, and vision problems. In addition, their growth can be delayed, and they can be more prone to infections.

How is sickle cell anemia diagnosed?

Sickle cell anemia is diagnosed with a blood test that checks for hemoglobin S protein.

Medical professionals use blood tests to screen newborns for a variety of diseases, including sickle cell anemia. If this test shows evidence of sickle hemoglobin, a second blood test is done to confirm a hemoglobin S diagnosis.

Sickle cell anemia can also be diagnosed in an unborn baby. Medical professionals do this by collecting a sample of amniotic fluid from a mother’s womb or from the placenta. Amniotic fluid comes from the sac surrounding the baby in the womb. The placenta connects the umbilical cord to the  womb.

This test looks for the presence of the mutated HBB gene instead of hemoglobin S protein. It can be done from eight to 10 weeks of pregnancy and onward.

A person can have this test at any age to find out if they carry the sickle hemoglobin gene and could pass it on to their children.

How is sickle cell anemia treated?

Although there is no cure for sickle cell anemia, treatments are available to relieve pain and prevent complications.

Commonly used medications include antibiotics to prevent infections, painkillers, and hydroxyurea to reduce the frequency of pain crises.

New treatments that have been approved or are under investigation include stem cell transplants, gene therapies, and compounds such as Endari (L-glutamine oral powder). The U.S. Food and Drug Administration recently approved Endari. Regulators in Europe, the Middle East and other areas are also considering approving it.


Sickle Cell Anemia News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.