Determination of the cause A History 1. Drug administration 2. Exposure to toxic chemicals 3. Family occurrence 4. Recent transfusions 5. menstruation(woman) 6. ingestion(child) 7. chronic disease 8. Age at onsetI. Determination of the cause: A. History 1. Drug administration. 2. Exposure to toxic chemicals 3. Family occurrence. 4. Recent transfusions 5.menstruation(woman) 6.ingestion(child) 7.chronic disease 8. Age at onset