High red blood cells include relative and absolute increases, and their severity varies depending on the condition, and cannot be generalized to say that they are serious or not serious. 1. Relative increase: common in frequent vomiting, sweating, extensive burns, diabetic ketoacidosis, uremia, severe diarrhea and other diseases. 2. Absolute increase (1) Secondary elevation: physiological elevation is common in newborns and people living in highland areas, and pathologic elevation is seen in severe chronic cardiopulmonary diseases, such as obstructive emphysema, pulmonary heart disease, cyanosis congenital heart disease and other diseases. (2) Primary elevation: it can be seen in diseases such as true erythrocytosis. The cause of increased erythrocytes should be specifically consulted with the clinician to further identify the cause of the disease for diagnosis and treatment, and please follow the doctor’s instructions for medication.