MDS stands for Myelodysplastic Syndromes, which are a group of diverse bone marrow disorders in which the bone marrow does not produce enough healthy blood cells. MDS is considered a type of cancer. The exact causes of MDS are unknown, but potential triggers include radiation and chemotherapy for cancer, long-term exposure to certain environmental or industrial chemicals, and aging. MDS is primarily a disease of the elderly, but it can affect younger patients as well. Symptoms of MDS rarely appear in the early stages. MDS is not inherited. Treatment options for MDS include supportive care, drug therapy, and chemotherapy with allogeneic stem cell transplant.