Sickle cell disease is an inherited group of disorders in which red blood cells change into sickle or crescent moon shapes. This happens when a child inherits two copies of the sickle cell gene mutation, one from each parent. With sickle cell trait, a child gets one copy of the sickle cell gene mutation from only one parent.

While the blood might contain some sickle cells, people with sickle cell trait generally don't have symptoms. Potential complications for people with sickle cell trait include sudden cardiac death with extreme dehydration. Organ damage and blood clots also can happen with dehydration or low oxygen levels at high altitudes.

People with sickle cell trait don't usually need treatment. But they are carriers of the disease, which means they can pass the gene to their children. People with this condition can see a genetic counselor before trying to conceive to better understand the risk of having a child with sickle cell disease.