Platelets are disk-shaped cells that are essential for blood coagulation. Aplatelet count determines the number of thrombocytes in blood available for promoting hemostasis and assisting with blood coagulation after injury. It also is used to evaluate the patients potential for bleeding; however, this is not its primary purpose. The normal count ranges from 150,000 to 350,000/mm3. a count of 100,000/mm3 or less indicates a potential for bleeding; count of less than 20,000/mm3 is associated with spontaneous bleeding.