The etiology and mechanism of long mouth ulcers are not yet clear, and are related to a variety of factors, such as genetics, diet, spirituality, trauma and so on. 1. Mouth ulcers are a painful ulcerated spot that appears on the mucous membrane of the lips, palate, and tongue and cheeks in the mouth. Its etiology is not yet clear, may be due to genetic factors, or may be improper diet, such as lack of vitamins, iron, zinc and other nutrients. 2. When the body’s mental stress, there may be anxiety, irritability, nervousness and other emotions, leading to poor sleep, the body’s immune system decreases, easy to cause mouth ulcers. 3. Or may be the consumption of sharp food, such as potato chips, shelled seafood and other foods, caused by the mucous membrane scratch or abrasion, as well as their own teeth accidentally bite, may cause mouth ulcers. In particular, people with low immunity are more susceptible to mouth ulcers compared to normal people. Once diagnosed with canker sores, patients need to take into account their own situation and actively cooperate with doctors to take relevant treatment measures to avoid delaying the condition.