What is MDS? | Aplastic Anemia and MDS International Foundation

What is MDS?

MDS (myelodysplastic syndromes) is a group of disorders in which your blood-forming stem cells are defective and fail to make healthy, mature blood cells. With MDS, patients have low blood counts for at least one blood cell type and blood cells look abnormal under a microscope. Doctors must do a bone marrow biopsy to be certain of the diagnosis. Symptoms and the course of MDS vary for each patient depending on which blood cells are affected.