Casson viscosity is an indicator that is closely related to whole blood viscosity and is one of the indicators of hemodynamics. A high karlson viscosity means that the viscosity of the whole blood is high, which means that the whole blood is less mobile and more susceptible to hyperviscosity and thrombotic or embolic disorders. High kasom viscosity can be caused by an increase in blood cells, such as an increase in the number of red blood cells, an increase in the number of platelets and poor deformability of red blood cells, and a significant local increase in kasom viscosity. Also, changes in the solute composition of the plasma may cause an increase in kasom viscosity, such as a significant increase in blood glucose, a significant increase in lipids, a significant increase in fibrinogen concentration, etc. The kasom viscosity may also increase significantly. Patients with multiple myeloma may also have increased kasone viscosity due to the secretion of large amounts of monoclonal immunoglobulins by plasma cells, resulting in hyperviscosity.