Bleeding is the main clinical manifestation of hemophilia. Patients have a lifelong tendency to bleed spontaneously, after minor injuries and surgery for a long time, and heavy cases can develop both after birth, while light cases develop a little later. 1, skin, mucous membrane bleeding: because the subcutaneous tissue, gums, tongue, oral mucosa and other parts are easy to injury, so it is the bleeding site, young children are more often seen in the frontal collision bleeding, hematoma, but skin, mucous membrane bleeding is not the characteristics of the disease. 2. Joint hemorrhage: Joint hemorrhage is a common clinical manifestation in patients with hemophilia A. It often occurs after trauma/walking for too long or exercise and causes synovial hemorrhage, mostly in the knee joint, followed by the ankle, hip, elbow, shoulder and wrist joints. 3.Muscle bleeding and hematoma: It often occurs in heavy hemophilia A, mostly after trauma/muscle activity for too long, mostly in the muscle groups that exert force. 4.Hematuria: Patients with heavy hemophilia A may have microscopic hematuria or carnal hematuria, mostly without pain or history of trauma, but with symptoms of renal colic if there is ureteral blood clot formation. 5. Pseudotumor (hemophilic hematocyst): cysts can occur in any part of the body, mostly in the thighs, pelvis, calves, feet, arms and hands, and sometimes in the eyes. 6, bleeding after trauma or surgery: various degrees of trauma, minor surgery can cause persistent and slow bleeding or hemorrhage. 7, bleeding from other parts: Gastrointestinal bleeding can be manifested as vomiting blood, black stool, bloody stool or abdominal pain, and most patients have primary lesions such as gastric and duodenal ulcers; hemoptysis is mostly related to primary lesions such as tuberculosis and bronchiectasis; sublingual hematoma can cause displacement of the tongue, and if the hematoma develops towards the neck, it often causes respiratory distress; intracranial hemorrhage is often the cause of death in patients with hemophilia.