What sort of problem is aplastic anemia?

Low bone marrow: Aplastic anemia is a disorder of the bone marrow in which it is low in cells (hypoplastic) or completely gone (aplastic). The causes and potential treatments are beyond the scope of this answer....

Aplastic anemia: Aplastic anemia is a serious problem of the blood sytem and bone marrow. The problem is that the bone marrow, where new blood cells are normally made, stops producing new cells, so you end up with low red blood cell counts, low white blood cell counts, and low platelet counts. The causes may be nutritional, cancer-related, toxin-related (eg, certain drugs), or genetic. See a hematologist.