Red blood cells that contain normal hemoglobin are disc-shaped and flexible, so they move easily through both large and small blood vessels. People with sickle cell anemia inherit a defective hemoglobin S gene that can cause rigid protein strands to form within red blood cells. This causes the cells to become shaped like a sickle, the farming tool with a semicircular blade like a crescent moon, giving both the cells and the disease their name.
These sickle-shaped cells are not flexible and can stick to vessel walls, causing inflammation in the blood vessels and blockages that can stop or slow the flow of blood.
The body, which is always making new red blood cells to replace the old cells, may have trouble keeping up with how fast the cells are being destroyed. This leads to an overall shortage of red blood cells in the body and, consequently, anemia.
In addition to anemia, the disease can cause other health problems, including infections, stroke, and kidney disease. These health issues can be long term and can reduce life expectancy.
Causes and Risk Factors of Sickle Cell Anemia
To have sickle cell anemia, a person must inherit two sickle hemoglobin genes, one from each parent. People with sickle cell trait (meaning they inherited only one sickle hemoglobin gene) generally don't have symptoms of sickle cell disease, but they can pass the sickle hemoglobin gene on to their children.
Having a family history of sickle cell disease increases your risk for the disease.
Duration of Sickle Cell Anemia
Prevention of Sickle Cell Anemia
There is no known way to prevent sickle cell anemia. However, you can find out if you carry the gene mutation through a simple blood test. If you don’t have sickle cell anemia but people in your family do, you may have inherited one sickle cell gene; this is referred to as sickle cell trait. If you carry the gene, your chances increase for having a child with either the disease or sickle cell trait.
To be born with sickle cell anemia, a child must inherit two sickle cell gene mutations, one from each parent.
If you carry the mutated gene and your partner carries the mutated gene, there is a 1 in 4 chance that your child will have sickle cell anemia.
If one of you carries the trait, there is a 1 in 2 chance that your child will also carry the trait.
A few simple steps can help prevent and reduce the number of pain crises:
- Drinking plenty of water
- Avoiding getting too hot or cold
- Avoiding exposure to high altitudes
- Avoiding places or situations where there might be low oxygen levels, such as mountain climbing or extremely intense exercise
Research and Statistics: How Many People Have Sickle Cell Anemia?
Related Conditions and Causes of Sickle Cell Anemia
Resources We Love
American Sickle Cell Anemia Association
This organization, founded in 1971, is the oldest sickle cell research, education, and social services organization in the United States. On its website, you can find information for support groups in your area.
American Society of Hematology
The world’s largest professional society concerned with the causes and treatments of blood disorders, including sickle cell anemia, ASH provides news on clinical and research advances on its website.
Be the Match
This organization's website has the latest information about blood or bone marrow transplants, along with information about joining clinical trials related to the disease.
National Organization for Rare Disorders
A great resource for information about sickle cell disease, this group's website links to current clinical trials and offers valuable information for patients and caregivers.
Sickle Cell Disease Association of America
On this site you’ll find information about the organization's peer-to-peer mentoring program, which helps adolescents and young adults as they transition into adult sickle cell health services. It also features a provider network and advocacy and research information.
Sickle Cell Society
On this site you can read blog posts by people with sickle cell disease, sharing their experiences and challenges that accompany living with the disease.
Editorial Sources and Fact-Checking
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About Sickle Cell Disease. National Human Genome Research Institute. May 26, 2020.
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