- Toxins or medications that cause generalized BM suppression→ etoh, chemotherapy, radiation, bactrim, linezolid, penicillin, other
- Etoh also suppresses megakaryocytes directly
- Other dz affecting bone marrow function→ leukemia, MDS
- Infections, including: Parvo, HIV, CMV, EBV, Hepatitis, TB, Fungal
- Nutritional deficiencies: B12, folate