Thrombocytopenia: A Low Platelet CountLow levels of platelets in the body are known as Thrombocytopenia. Platelets is a type of blood cell, helps in blood clot and stop bleeding. People tend to bleed more readily when their platelet count is low. Adults typically have between 1,50,000 and 4,50,000 platelets per microliter of blood. A platelet counts below 1,50,000 indicates Thrombocytopenia.