Red blood cells contain hemoglobin. Hemoglobin helps red blood cells carry oxygen from the lungs to other parts of the body. People with normal hemoglobin have mostly Hemoglobin A in their red blood cells. People with sickle cell disease have mostly sickle or Hemoglobin S (Hb S) in their red blood cells. Hb S is an abnormal type of hemoglobin. In people with sickle cell disease, Hb S causes the red blood cells to change from a round shape to a sickle or banana shape. Also, Hb S causes the red blood cells to become rigid and sticky. This leads.
