What Is It?
Myelodysplastic syndromes (MDS) are diseases in which the bone marrow does not make enough healthy blood cells. Bone marrow is the soft, inner part of bones. Normally, it produces three kinds of blood cells:
red blood cells, which carry oxygen
white blood cells, which fight infection and disease
platelets, which help prevent bleeding by causing blood to clot.
Healthy bone marrow makes immature cells called stem cells that develop into red and white blood cells and platelets.
In MDS, the bone marrow cannot produce the right kind of blood cells. These abnormal cells either die in the bone marrow or soon after they enter the bloodstream. As a result, people with MDS don't have enough healthy blood cells and are said to have low blood cell counts. This can lead to: