Nelson, MDMedically reviewed by Douglas A. Nelson, MD Thrombocytosis, or a high platelet count, is diagnosed when platelet levels are greater than 450,000 platelets per microliter of blood.

8 Platelet adhesiveness (or, more properly, the retention of platelets in a glass bead filter) was measured by a modification of Salzman's method. 8 Venous blood was mixed (9:1) with either 3.2 ...