Thrombocytopenia is a condition in which there is a deficient number of circulating platelets.

Thrombocytopenia may be congenital or acquired.

The acquired form is more common, especially among elderly. In either case, it usually results from decreased or defective production of platelets in the bone marrow (for example, in leukemia, aplasticanemia and with toxicity from certain drugs), increased destruction outside the marrow caused by an underlying disorder (such as cirrhosis of the liver,...