Sickle cell disease is characterized as a group of inherited blood disorders where there is an abnormality on the hemoglobin gene. The four common syndromes include the trait, sickle cell anemia, sickle hemoglobin C, and sickle beta thalassemia.

Commonly, when people refer to sickle cell disease it is assumed that it is an interchangeable term for sickle cell anemia. Sickle cell anemia shares many common effects with the other forms of sickle cell disease, but most often HbSS causes more frequent pain crises and other complications.

A normal red blood cell is round, flexible, and has the ability to pass through small blood vessels. When a sickle red blood cell travels and loses its oxygen it also loses its round, flexible shape and becomes elongated or crescent shaped, rigid and blocks blood vessels. When blood vessels are blocked, some areas will no longer be receiving a blood supply causing severe pain to the individual.

Sickle beta thalassemia disease is the least common syndrome next to the trait, sickle hemoglobin C disease, and sickle cell anemia. Although sickle hemoglobin C disease does not have a significantly higher incident rate, it is more commonly found in those of African and Hispanic descent. These two diseases cause more difficulties than the sickle cell trait, but are not as severe as sickle cell anemia.

People living with HbSC or HbS/B+ disease may have such complications as acute chest syndrome, cerebrovascular accidents (stroke), and pain crises. Often pain crises occur due to stress, dehydration, and being in high altitudes for long periods of time. These causes of pain crises are common throughout all forms of sickle cell disease.