Fibrin is a protein with blood clotting function in the body, generally synthesized by the liver, when the liver has liver function damage or other diseases of the liver, resulting in liver insufficiency, it will cause the body’s fibrin to be low. This is usually after the liver synthesis of fibrinogen dysfunction, caused by the plasma concentration of fibrinogen decreased, will affect the body’s coagulation function, which further causes the patient easy to bleed, as well as petechiae, ecchymosis occurs under the skin possibility. Another situation is that the patient may have primary and secondary hyperfibrinolysis, causing hypofibrinogenemia. Further investigation is needed to see if the patient has an acute inflammatory or septic condition that causes hyperfibrinolysis. For liver-induced low fibrin, patients need to actively draw blood to check whether there is hepatitis B and hepatitis C, and if necessary, need to check hepatitis B DNA and hepatitis C RNA, which may be due to viral replication, combined with the damage of the patient’s liver function, which further causes low fibrin.