If the red blood cell count is slightly elevated, then there is no obvious effect on the human body, and drinking more water can make the red blood cells lower. If the number of red blood cells is seriously high, we should pay attention to it, and need to find out the reason in time. Higher red blood cells are divided into physiological and pathological causes. 1. Physiological causes of high red blood cells: such as living in the plateau area residents, after strenuous exercise, drinking too little water or excessive sweating, excessive water discharge, etc., caused by the increase in red blood cells do not need medication, through the diet can be adjusted, moderate amount of water can reduce red blood cells. 2. Pathological causes: such as continuous violent vomiting, extensive burns, severe diarrhea, sweating and chronic cardiopulmonary diseases, tumors and renal diseases, myeloproliferative diseases, such as eukaryocytosis, etc., at this time, drink more water will not make the red blood cells return to normal levels. Specialized treatment is needed, such as oral hydroxyurea for patients with true erythrocytosis. It is recommended to consult a doctor if there is any abnormality in the test, and further treatment and therapy will be carried out after the cause is clarified under the guidance of the doctor.