Causes of bleeding: First, trauma, when the skin is broken, blood vessels rupture or tissue damage there will be blood outflow, need to promptly deal with trauma to stop bleeding. Second, coagulation factor deficiency, when the blood does not run in the blood vessels within its coagulation factors will promote blood clotting, but such as liver problems will lead to a lack of coagulation factors, will lead to continuous blood outflow. Third, the lack of platelets or abnormal function, blood clotting requires the participation of clotting factors, fibrinogen, platelets, if the body is not able to generate enough platelets inside or platelets are defective, it will lead to continuous bleeding. Fourth, re-rupture of the ligated blood vessel after surgery can also cause bleeding. Fifth, the corrosion of digestive juices, for example, when suffering from acute pancreatitis pancreatic juices will flow into the abdominal cavity to corrode the tissue, resulting in bleeding in the abdominal cavity.