Plasma is a blood product commonly used in clinical practice. Plasma is the liquid portion of blood that remains after all blood cells have been separated. In general, plasma is often used in patients with coagulation disorders, such as hemophilia a, hemophilia b, vitamin K deficiency, diffuse intravascular coagulation, etc. Plasma can be transfused because it is rich in coagulation factors, which can replenish the coagulation factors in the body and thus improve the symptoms of coagulation disorders, and it can also be transfused to treat patients with severe immune deficiency. In addition to coagulation factors, plasma is also rich in immunoglobulins, which can effectively improve the immunity of patients. Plasma can also be transfused for patients who are bedridden for a long time, old and weak, and for patients with malignant tumors when they are weak. Plasma is often used in patients with coagulation disorders or immune deficiencies.