Sickle cell trait occurs when an individual inherits one copy of the sickle cell hemoglobin gene and one normal, or unchanged, copy of the hemoglobin gene. Hemoglobin is inside red blood cells and helps carry oxygen around to all parts of body. An individual with sickle cell trait does not have sickle cell disease, but is a trait carrier. Sickle cell disease only occurs when an individual inherits two copies of the sickle cell gene. The majority of people with sickle cell trait will be free of symptoms and will live a normal life. Sometimes individuals with sickle cell trait may have some of the health complications seen in sickle cell disease. Certain conditions such as high altitude, low oxygen level, dehydration, increased pressure in the atmosphere, or very intense physical activity can increase the risk that these symptoms occur in some people with sickle cell trait. About 1 in 12 African Americans and 1 in 100 Latinos has sickle cell trait. However, it is possible for anyone of any race or nationality to be a carrier for sickle cell disease.