Blood sedimentation is the abbreviation of erythrocyte sedimentation rate, which refers to the rate of erythrocyte sedimentation under certain conditions. The normal value of hematocrit, which is commonly used in China and abroad, should be below 15 mm/h for men and below 20 mm/h for women. In many physiological and pathological conditions, such as during menstruation, under 3 months of pregnancy, and in elderly people over 60 years of age, the hematocrit can increase, so the hematocrit test is non-specific, but a continuously increasing hematocrit indicates pathological conditions, such as infection, inflammation, and tumors. Causes of increased hematocrit: 1. Inflammatory diseases, such as acute bacterial inflammation, with accelerated hematocrit in 2 to 3 hours; 2. Various acute systemic or local infections, such as active tuberculosis, nephritis, myocarditis, pneumonia, septic encephalitis, pelvic inflammatory disease, etc.; 3. Various collagenous diseases, such as rheumatoid arthritis, systemic lupus erythematosus, scleroderma, arteritis, etc.; 4. Tissue injury and necrosis, such as extensive tissue necrosis or injury, injury caused by major surgery, myocardial infarction, pulmonary infarction, fracture, severe trauma, burns and other diseases can also accelerate the blood sedimentation; 5, suffering from severe anemia, blood diseases, chronic hepatitis, liver cirrhosis, multiple myeloma, hyperthyroidism, heavy metal poisoning, malignant lymphoma, macroglobulinemia, chronic nephritis and other diseases, the blood sedimentation can also show a significant tendency to accelerate.