When the width of red blood cell distribution in the human body is high, blood flow will gradually slow down, the body’s tissues will receive less oxygen and nutrients, too many aging and hardened red blood cells will agglomerate, aggravate blood stickiness and clotting will occur, and even blood clots will appear, causing blood vessel embolism, which will lead to ischemic cardiovascular and cerebrovascular diseases. The following is an explanation of how high red red blood cell distribution width should be diagnosed. Blood thickening is not an independent disease, but there are many clinical diseases such as atherosclerosis, cerebral thrombosis, myocardial infarction, hypertension, diabetes mellitus, obstructive retinitis, and chronic liver and kidney diseases that are closely related to blood thickening. This is because when the viscosity of human blood increases, the blood flow slows down, the oxygen and nutrients available to the body’s tissues are relatively reduced, especially the aging and hardening of excessive red blood cells, the occurrence of red blood cell aggregation, the aggravation of blood thickening and clotting, the appearance of blood clots, causing vascular embolism, and thus the occurrence of ischemic cardiovascular and cerebrovascular diseases. It is recommended to keep track of changes in blood pressure, blood glucose and lipid levels to reduce the incidence of cardiovascular accidents. Regularly check erythrocyte enolase, RDW, erythrocyte volume index, erythrocyte permeability fragility test, and erythrocyte life span. Eat a regular light diet, low salt and low fat diet, appropriate physical exercise to enhance physical fitness. Quit smoking and drinking bad habits and keep bowel movements smooth.