Sickle cell trait or sickle cell disease? What's the difference
Uriel E. Owens Sickle Cell Disease Association · 3 min read
The short answer
Sickle cell trait means a person carries one sickle gene. Sickle cell disease means they inherited a sickle gene from each parent. People with the trait rarely have health complications. Sickle cell disease is an inherited blood disorder, and living with it is easier with a care team you trust.
What sickle cell disease is
Sickle cell disease is an inherited blood disorder that affects the red blood cells. Normal red blood cells are round and shaped like a donut. They carry oxygen and nutrients throughout the body.
Sickle cells are different. They are rigid and abnormally shaped, they cannot carry oxygen well, and they have a shorter life span than normal red blood cells. Their sickle shape can clog blood vessels and stop oxygen from reaching tissues and organs. When sickled cells stick together and block blood flow, it is called a vaso-occlusive crisis, or pain crisis. It is the most common complication of sickle cell disease.
What sickle cell trait is
People who carry the gene for sickle cell disease have what is known as sickle cell trait. They have one sickle gene and one usual gene. Many trait carriers do not know they have it, and they rarely have health complications, except under very extreme conditions.
People with sickle cell trait are still able to donate blood. The association's site also notes that sickle cell trait developed out of a resistance to malaria.
How each one is passed down
Every child gets one gene from each parent. A child who gets a sickle gene from both parents has sickle cell disease. A child who gets one sickle gene has the trait.
That is why two parents who both have the trait can have a child with sickle cell disease. For each of their children there is a one in four chance of sickle cell disease. You can try it yourself in the passed-down game on our About Sickle Cell page.
Quick self-check
Trait or disease?
Read each line and tap Trait or Disease.
Question 1 of 5
A person has one sickle gene and one usual gene.
That is sickle cell trait: one sickle gene, carried from one parent.
Question 2 of 5
A child got a sickle gene from both parents.
That is sickle cell disease. A sickle gene from each parent means the disease, not the trait.
Question 3 of 5
Many people with this do not know they have it.
Trait carriers may not know they have the trait, and they rarely have health complications.
Question 4 of 5
Rigid, sickle-shaped cells can clog blood vessels and cause pain crises.
That describes sickle cell disease. A pain crisis happens when sickled cells stick together and block blood flow.
Question 5 of 5
People with this are still able to donate blood.
People with sickle cell trait are still able to donate blood.
This quiz cannot tell you whether you or your child has the trait. Ask your doctor about testing, and call the association if you need help finding care.
Why knowing matters
Because many people with the trait do not know they have it, a family can carry it without knowing. Knowing whether you have the trait helps you understand what is possible for your children, and it gives you something concrete to talk about with your doctor.
If you already live with sickle cell disease, or you love someone who does, the association's site puts it simply: having a care team you know and trust is crucial to navigating life with sickle cell. Treatment decisions belong with your doctor or hematologist.
Where to get help in Kansas City
The University Health Sickle Cell Center is at 2301 Holmes in Kansas City, Missouri, and can be reached at 816-404-4290. The association itself offers public education at health fairs and community events, workshops, and one-on-one counseling for individuals and families. Its office is at 444 Minnesota Ave., Suite 300, in Kansas City, Kansas, open Monday to Friday, 10 am to 4:30 pm CT.
For trusted national information, the association points families to the National Heart, Lung and Blood Institute, the National Institutes of Health and the Sickle Cell Disease Association. Our helpful links list them all in one place.
Questions people ask
Can a person with sickle cell trait get sickle cell disease later?
No. The trait and the disease come from the genes a person is born with. Someone with the trait has one sickle gene, and that does not change. Ask your doctor if you have questions about your own health.
How do I find out if I have the trait?
Ask your doctor about testing. If you need help finding care in Kansas City, the association can point you in the right direction.
If both parents have the trait, will their child have sickle cell disease?
Not necessarily. For each child of two parents with the trait, there is a one in four chance of sickle cell disease.
Keep reading
Back to school with sickle cell: what to share with the school nurse
A simple plan for the first conversation with your child's school, plus a checklist you can tick off.
Living well with sickle cell: everyday habits people talk about
Everyday habits from national guidance, and how to find the right help in Kansas City.
Sources: the association's own site, and the National Heart, Lung and Blood Institute, which the association lists in its Helpful Links.