The mouth is always long ulcers may be caused by the following reasons: 1, due to poor dietary habits, like to eat spicy, too hot, too hard food, these mechanical or chemical stimulation will cause the oral mucosa ulcers. 2, due to poor work and rest habits caused by people who like to stay up late, black and white often have immune disorders, such people are also prone to ulcers. 3, due to infection caused by, if If many teeth in the mouth are suffering from caries, or have pulpitis, periapical inflammation, wisdom teeth peri-coronitis, poor oral hygiene, such people have a lot of pathogenic bacterial factors in their mouths, which can easily induce ulcers. 4, mental and psychological factors are also one of the causes of ulcers, such as long-term tension, anxiety, depression, the incidence of ulcers is also higher.