Blood viscosity is the consistency of the blood and an indicator of whether the blood is flowing smoothly enough through the blood vessels. When blood viscosity is high, blood flow is slow, blood stagnation tends to occur, and patients are prone to thrombosis or embolic disorders. Causes of increased blood viscosity. Common causes include an increase in the number of blood cells, poor deformability of red blood cells, or an increase in the number and adhesiveness of platelets. Changes in the solute composition of the plasma, such as increased blood glucose, increased lipids, increased antibodies and increased fibrinogen concentration, can also cause increased blood viscosity. If there is an increase in blood viscosity, the first step is to identify the cause of the increase in blood viscosity, and then give the corresponding treatment, such as high blood viscosity caused by red blood cell increase, it is necessary to reduce red blood cell treatment. If the blood viscosity is high due to hyperglycemia or hyperlipidemia, it should be treated by hypoglycemia and hypolipidemia.