If there is a bloody smell in the mouth, consider the following three situations: first, the existence of ENT diseases, such as rhinitis and tonsillitis, there may be local inflammatory exudation, blood seepage into the mouth. Second, gastroenterological diseases, patients with esophageal bleeding or gastric bleeding can reflux into the oral cavity, so that the taste of blood inside the mouth. Third, the most common is gingivitis and periodontitis inside the mouth. When there is gingivitis, periodontitis, the gum tissue will appear red, swollen, fragile, easy to bleed, often making the mouth inside the presence of the bloody taste, the need to go to the Department of Dentistry for dental cleaning treatment.