1. Certain medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs), antibiotics, anticonvulsants, and antipsychotics.
2. Chemotherapy and radiation therapy used to treat cancer.
3. Autoimmune diseases, such as lupus and rheumatoid arthritis.
4. Viral infections, such as HIV, hepatitis, and Epstein-Barr virus.
5. Bacterial infections, such as sepsis.
6. Exposure to certain toxins, such as benzene.
7. Bone marrow disorders, such as aplastic anemia.
8. Genetic disorders, such as Fanconi anemia.