High blood concentration means that the viscosity of blood increases, and after the increase of blood viscosity, the blood flow will be slowed down, and hyperviscosity will easily occur, even inducing thrombosis and embolic diseases. Therefore, the common symptoms after high blood viscosity: First, the central nervous system ischemia, hypoxia symptoms, because the central nervous system is the most sensitive to hypoxia, the patient can be manifested as headache, dizziness, dizziness, forgetfulness, tinnitus, blurred vision, and sometimes visual impairment, numbness and tingling of limbs and so on. Secondly, increased blood concentration can also be caused by increased blood sugar and increased blood fat, so there will be symptoms related to high blood sugar, such as thirst, drinking, urination and wasting. If the increased blood viscosity is caused by multiple myeloma, the patient may also have pain in bones, mainly in the waist and hip joints, as well as a series of symptoms of multiple myeloma such as anemia, proteinuria and renal failure.