These are viral infections like parvo virus, rubella, mumps, Epstein barr, hepatitis C, aplastic anemia due to radiation if received,
thiazide diuretics can suppress platelet production, long term alcohol, vitamin B12 and folate deficiency.
Increased destruction of platelets can be seen due to both immune and non immune related conditions. Certain drugs like sulphonamides, carbamazepine, quinine, acetaminophen and rifampin can all cause drug induced thrombocytopenia.