Poor coagulation is a group of clinical syndromes in which the patient is prone to bleeding due to the lack or decreased activity of coagulation factors caused by various reasons, resulting in the failure of the coagulation pathway to complete successfully. In clinical practice, the most common disorders of poor coagulation are congenital deficiencies of coagulation factors: e.g. hemophilia A, hemophilia B, vascular hemophilia, congenital fibrinogen deficiency, congenital coagulation factor VII deficiency, coagulation factor XIII deficiency, etc. Also, patients with severe liver disease can have poor coagulation because the liver is the main organ that produces various coagulation factors, and when the liver is damaged, the production of coagulation factors is reduced, commonly in cirrhosis, alcoholic hepatitis, etc. Also, in diffuse intravascular coagulation, the concentration of clotting factors decreases due to massive consumption of clotting factors, and poor coagulation also occurs.