Sickle Cell Trait

Article Translations: (Spanish)

What Is Sickle Cell Trait?

Sickle cell trait is a blood condition that gets passed down through some families in their genes. It doesn’t usually cause health problems, and it can’t turn into sickle cell disease.

A person has sickle cell trait when they inherit a copy of the “sickle cell gene” from one of their parents. With only 1 copy of the sickle cell gene, they don’t have sickle cell disease, but they can pass a copy of the gene on. A person with sickle cell trait is also called a “carrier.”

How Do Sickle Cell Trait and Sickle Cell Disease Differ?

Sickle cell trait doesn’t usually cause health problems. Symptoms are rare and usually can be prevented.

Sickle cell disease is a blood disorder where red blood cells are curved instead of round. The curved cells can get stuck in and block small blood vessels. Blood can't flow normally, which can lead to pain and organ damage. People with sickle cell disease need lifelong medical care.

Do People With Sickle Cell Trait Have Health Problems?

Sickle cell trait can cause problems, but not everyone has them. Some people with sickle cell trait could get:

muscle cramps during or after hard exercise
problems after an eye injury
blood in their pee
sudden pain on the left side of the belly
pain at high altitudes

A person who has any of these symptoms should talk to their doctor.

How Does Someone Get Sickle Cell Trait?

Everyone has 2 copies of a gene called the beta-globin gene. We inherit one from each parent. This gene tells the body how to make hemoglobin (pronounced: HEE-muh-glow-bin). Hemoglobin is the part of red blood cells that carries oxygen.

A person gets sickle cell trait if they inherit 1 normal beta-globin gene and 1 sickle beta-globin gene (sickle cell gene).

Sickle cell trait is most common among people whose ancestors came from hot tropical climates, but people from all different backgrounds can have it. In fact, many people have the condition but don’t know it.

Why Is It Important to Know My Sickle Cell Trait Status?

Knowing your status means knowing if you have sickle cell trait. It’s important to find out if you have sickle cell trait because people who do need to exercise safely to prevent problems. That’s why if you get a sports physical for school, you might see a question asking about sickle cell trait.

How Can I Find Out if I Have Sickle Cell Trait?

First, ask a parent or your doctor. They might know because every baby born in the U.S. (and in some other countries) is tested at birth.

If they don’t know your status, your doctor can send you for a blood test to find out. The same test can tell if someone has sickle cell disease, thalassemia, or other health problems that affect the blood.

After you get the test, your doctor will tell you what the results mean.

What if I Have Sickle Cell Trait?

If you have sickle cell trait, you can live a normal life. It’s best to:

Talk to your doctor. During your yearly checkup or sports physical is a good time to bring it up. Ask questions and find out the best ways to take care of yourself.
Drink plenty of water, especially if you exercise hard, spend a lot of time outside in the heat, or plan to travel to a high elevation.
Exercise safely. Pace yourself. Take breaks if you’re tired. Drink lots of water. If you don’t feel well during or after exercise, speak up. Tell the coach, a trainer, or a parent.
Learn all you can. If you have kids someday, there's a chance your child could be born with sickle cell trait or sickle cell disease. So it's helpful to learn more about your genes before you start a family. A genetic counselor can tell you more. You also can learn more about sickle cell trait from the CDC.

Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor.