High red blood cell distribution width is an abnormal state of viscous blood. Viscous blood flows slowly in the blood vessels and affects the blood supply to the organs. Most middle-aged and elderly patients with high RBC distribution width have atherosclerosis, hypertension, diabetes and other medical conditions. In conclusion, high erythrocyte distribution width often lacks specific symptoms, and five signals generally appear before the onset of the disease to facilitate self-examination by patients. 1, neurological symptoms: morning dizziness, heavy head feeling, sleepiness after lunch, headache, head swelling, tinnitus, forgetfulness, weakness, tiredness, numbness of limbs, palpitation and shortness of breath. 2, eye symptoms: high blood viscosity, blood can not fully nourish the optic nerve, resulting in temporary ischemia of the optic nerve and retina, resulting in vision loss, often in the twisting of the neck when a transient vision blurred, serious cases can be blind. 3, bleeding symptoms: common nose, gum bleeding and skin mucosa bleeding spots, petechiae, etc. 4, thrombosis: can occur in the cerebral arteries, coronary arteries, and cause the corresponding symptoms, can also occur phlebitis, etc. 5.Blood is easy to coagulate: when drawing venous blood, the blood quickly coagulates in the syringe. For middle-aged and elderly people, especially those who already suffer from hypertension, arteriosclerosis and diabetes, as long as three of the above five symptoms appear, we should pay attention to them and go to the hospital to check blood coagulation time, platelet function, immunoglobulin, blood lipids, blood rheology and other items.