Platelet pressure is the volume of platelets in peripheral blood as a percentage of blood volume. A high platelet pressure means that the number of platelets in peripheral blood is out of the normal range, and the higher the degree to which the number of platelets is out of the normal range, the higher the platelet pressure will be. In clinical practice, there are two types of increased platelet count, one is reactive platelet count increase, such as severe trauma, infection, major surgery, bleeding and other stressful conditions, the platelet count will appear reactive increase, then the platelet pressure will also appear significantly increased, but when the trigger is removed, the platelet count will gradually drop to the normal range. The second condition is primary platelet hyperplasia, which is a myeloproliferative disorder. The number of platelets in the peripheral blood reaches an abnormally high level and the patient forms a thrombotic disorder, sometimes manifested as bleeding from the nose and gums, which requires clinical emergency management, the most effective method being to use a blood cell separator to separate out the excessive platelets in the peripheral blood and then take hydroxyurea for maintenance treatment.