The red blood cell count is a measurement of the number of red blood cells per unit volume of blood and is one of the basic blood test items. A high red blood cell count is generally defined as a red blood cell count greater than 5.5×10^12/L in adult females and 6.0×10^12/L in adult males. a high red blood cell count is divided into physiologically high and pathologically high, which are analyzed as follows: i. Physiologically high: common in newborns, plateau residents, etc. Newborns are in a physiological hypoxic state before birth, so the red blood cell count is significantly high. Due to the thin atmosphere, the partial pressure of oxygen is relatively low, and the red blood cell compensatory proliferation is stimulated by hypoxia, and the bone marrow produces more red blood cells, which leads to a high red blood cell count. Pathologically high: 1. Patients with congenital heart disease, chronic lung disease and chronic carbon monoxide poisoning need to consume a large number of red blood cells to maintain oxygen supply due to hypoxia, resulting in a high red blood cell count; 2. Patients with severe vomiting, diarrhea, large burns and advanced gastrointestinal tumors are dehydrated, resulting in blood concentration, which leads to a relative increase in the organic fraction of the blood, resulting in a high red blood cell count. High RBC count.