Sickle Cell Disease affects 100,000 Americans each year. Healthy red blood cells are round and they move through small blood vessels to carry oxygen to all parts of the body by a protein called hemoglobin. In someone who has SCD, the red blood cells become hard and sticky and look like a C-shaped farm tool called a “sickle”. Sickle Cell Disease affects thousands of people throughout the world but is most common among those whose ancestors come from sub-Saharan Africa.