Blood rheology is usually used to check the viscosity of the blood, or whether the blood is flowing smoothly. The most important function of blood rheology examination is to determine whether thrombotic or embolic diseases have occurred and to diagnose them. If the blood rheology test reveals an increase in blood viscosity, for example, if the patient has severe coronary artery disease, myocardial infarction, or deep arterial thrombosis or venous thrombosis, it has obvious diagnostic and therapeutic value, especially for hypertensive patients. In patients with diabetes, coronary atherosclerotic heart disease, cerebrovascular disease, and hyperlipidemia, regular blood flow check and rechecking of blood flow is of obvious significance in treating the primary disease and preventing complications.