There are many causes of oral bleeding. The main ones are bleeding from oral mucosa such as gums and bleeding after tooth extraction surgery caused by systemic or local factors. It can also be determined from the oral cavity’s own source or the source of adjacent anatomical sites in the oral cavity. The most common site of bleeding from the oral cavity’s own mucosal source is the gums. The site of bleeding can be the entire gingiva or confined to individual gingiva. The most common causes are chronic gingivitis, periodontitis, interdental papillitis, and gingival hyperplasia. The gingival margin and gingival papillae are red, swollen, flaccid, and even hyperplastic. It usually causes bleeding when subjected to local mechanical irritation, the amount is not large and can stop on its own. After removal of local irritants such as tartar, soft tooth tartar and embedded food, the inflammation will quickly subside and the bleeding will soon stop. Less common cases, such as gingivitis and gingival tumors during pregnancy and necrotizing gingivostomatitis, may be accompanied by bleeding and pain in the gums and blood clots in the saliva in the morning. Long-term use of anticoagulant medications may also cause bleeding from the entire gums or from individual gum areas. Ulcers of the oral mucosa can also sometimes cause bleeding in the mouth. Examples include recurrent oral ulcers and cancerous ulcers, which cause localized vascular rupture. Sharp edges of poor restorations or sharp tips of retaining rings, and traumatic oral ulcers caused by occlusal trauma can also cause oral bleeding. In recent years, there has been a gradual increase in the number of cases of bleeding after tooth extraction and periodontal scaling (commonly known as scaling) due to the long-term use of anticoagulant drugs in middle-aged and elderly people. In addition, soft tissue injury during tooth extraction surgery, incomplete scraping of inflammatory granulation tissue in the extraction sockets, fracture of alveolar bone, excessive mouth rinsing and repeated wound irritation are also common local factors causing bleeding after tooth extraction. Bleeding from anatomical sites adjacent to the oral cavity may also manifest as oral bleeding, for example, nasopharyngeal cavity, pharynx, larynx and tracheal and pulmonary diseases may find bleeding symptoms in the oral cavity. However, depending on the amount of bleeding and the color of the blood, the differential diagnosis and symptomatic treatment can be made separately. Oral bleeding is often a common first symptom and/or complication of hematologic and hematopoietic disorders, mostly due to reduced platelet count or poor platelet quality such as idiopathic thrombocytopenic purpura, aplastic anemia, leukemia, and hypersplenism, resulting in oral mucosal bleeding or submucosal oozing of blood. Patients often present with full-mouth gingival swelling, heavy bleeding, and large clots in the mouth that are extensive and do not stop on their own. The treatment of oral bleeding must be tailored to the source and cause of bleeding, and different treatments must be taken to treat the symptoms in order to cure completely. If anticoagulant drugs are taken prophylactically, they can be stopped for about five days before oral treatment. However, after coronary artery disease, hypertension, pacemaker installation, vascular stenting, and heart valve surgery, anticoagulant medication cannot be stopped easily, and if necessary, a collaborative consultation with a relevant physician is required. When oral bleeding occurs, make sure not to suck repeatedly, overheat the diet, rinse the mouth repeatedly, etc. You can temporarily use cold compresses with ice packs or gauze compression to stop the bleeding, and go to the stomatology department for further consultation and treatment in a timely manner.