High erythrocytes, hemoglobin, and erythropoietic pressure indicate that the number of red blood cells, hemoglobin concentration, and erythropoietic pressure are outside the normal range, a condition most commonly associated with various causes of erythrocytosis. There are two types of erythrocytosis, secondary erythrocytosis and primary erythrocytosis. Secondary erythrocytosis is common in various chronic hypoxic diseases, such as chronic obstructive pulmonary disease, congenital cyanotic heart disease, etc. Due to long-term chronic hypoxia, the concentration of erythropoietin in the body increases, stimulating the proliferation of red blood cells, resulting in a significant increase in the number of red blood cells, hemoglobin concentration, and erythropoietic pressure, which will drop to normal when the cause is removed. Primary erythropoiesis is commonly seen in various myeloproliferative disorders, such as true erythropoiesis and primary thrombocytosis. Due to abnormally high blood cell counts, especially abnormally high red blood cell counts, abnormally high red blood cell counts, hemoglobin concentrations, and red blood cell pressure products also occur, and this condition often requires the application of drugs such as hydroxyurea and interferon.