Blood viscosity refers to the thickening of the blood caused by the increase of organic components in the blood, and it is not an independent disease. There are many clinical diseases such as atherosclerosis, cerebral thrombosis, myocardial infarction, hypertension, diabetes mellitus, obstructive retina, and chronic liver and kidney diseases, all of which are closely related to blood viscosity. This is because when the viscosity of human blood increases, the blood flow slows down, the oxygen and nutrients obtained by the body’s tissues are relatively reduced, especially the excessive red blood cells aging, hardening, occurring red blood cells sharply aggravate the blood thickening and clotting, blood clots, resulting in blood vessel embolism, thus occurring ischemic cardiovascular diseases. Someone’s image analogy is like a narrow road crowded with too many worn-out cars, which may break down and block the traffic at any time, or even poor transportation.