NIH Sickle Cell Cord Blood Research Program

What is sickle cell disease?

Sickle cell disease is an illness that can cause problems within a person's bloodstream. Red blood cells in the bloodstream carry oxygen to all parts of the body by using something called hemoglobin. Normal red blood cells contain normal hemoglobin and are shaped like doughnuts. These normal red blood cells are very flexible and move easily around the body. In sickle cell disease, the red blood cells contain sickle hemoglobin, which cause the red blood cells to change to a curved shape (sickle shape). These sickled, curved shaped red blood cells become stuck and form plugs in small blood vessels. These plugs stop blood flow and cause damage to body parts. The damage can occur anywhere blood flow is cut off the in the body. Depending on where it occurs, the blockage can lead to strokes; intense pain in the chest, arms, and legs; death and decay of tissues, especially in the joints; disease of the retina of the eye; slow healing sores; gallstones; kidney infections.