A high platelet count, also called platelet pressure, is one of the most important parameters of platelet function and is usually associated with an increase in the mean platelet volume and an increase in the width of platelet distribution. A high platelet count alone is usually not a definitive diagnosis and needs to be analyzed together with other tests. If the high platelet count is caused by an increase in the mean platelet volume, it usually indicates good bone marrow compensation and increased platelet destruction, which can be seen after hematopoietic suppression is lifted. A high platelet count is usually the first sign of a gradual recovery of hematopoietic function and can also be seen in women during pregnancy and is usually normal. In addition, it may be associated with various diseases such as anemia, cirrhosis of the liver, pheochromocytoma, and myeloproliferative neoplasm. If the high platelet ratio is caused by an increase in the width of platelet distribution, it can be seen in patients with infections, blood loss, hemolysis, etc., and some tumors. It can also be associated with a variety of diseases such as giant platelet syndrome, megaloblastic anemia, thrombophilia, and slow and acute myeloid leukemia. It is recommended that such patients have their platelet count reviewed regularly under the guidance of a physician and if it returns to normal levels, there is no cause for concern. If the platelet ratio is persistently high, it may be related to some diseases. It is recommended to improve other tests in time to clarify the specific causes and actively cooperate with the doctor for targeted treatment to avoid aggravation of the disease.