Hematocrit refers to the sedimentation rate of red blood cells, which is the result of the interaction between the gravitational force of the earth, the buoyancy of the plasma and the composition of the blood in the resting state. In case of high hematocrit, there may be various inflammatory diseases, tissue damage and necrosis, malignant tumors and other diseases, but certain physiological causes can also cause high hematocrit: 1. Physiological causes: age <12 years or >60 years, female menstruation and more than 3 months of pregnancy can have high hematocrit, which is usually associated with physiological anemia or increased fibrinogen content. Pathological causes: 1. Various inflammatory diseases: elevated blood sedimentation can occur 2-3 days after the occurrence of acute bacterial inflammation. Such as rheumatic fever, tuberculosis, etc., the onset of fibrinogen and immunoglobulin increase, blood sedimentation can be significantly increased; 2, tissue injury and necrosis: including trauma, surgical trauma, acute myocardial infarction, etc.. Such as acute myocardial infarction, blood sedimentation increases, mainly due to acute myocardial infarction when a large number of myocardial cells necrosis, causing accelerated sedimentation; 3, malignant tumors: rapid growth of malignant tumors can cause increased sedimentation, may be related to tumor cells secrete glycoprotein-like products, tumor tissue necrosis, secondary infection or anemia and other factors; 4, other: various reasons for the relative or absolute increase in plasma globulin, sedimentation can be increased In addition, some patients with anemia may have elevated sedimentation, such as chronic nephritis, liver cirrhosis, multiple myeloma, macroglobulinemia, B-cell lymphoma, systemic lupus erythematosus, subacute infective endocarditis, and black fever. In addition, in some patients with anemia, the blood sedimentation may be mildly elevated. In patients with atherosclerosis, diabetes mellitus, nephrotic syndrome, and mucinous edema, blood cholesterol is high and the blood sedimentation may also be elevated.