Mouth ulcers in babies can trigger symptoms such as fever, broken mouth, loss of appetite, irritability, and restless sleep. But it happens to a lot of babies. What should I do if my baby has a mouth ulcer? First, find the ulcer site. When a baby has an ulcer in the mouth, look carefully at the baby’s mouth and find the specific part of the mouth ulcer. If the ulcer is at the buccal mucosa, further find the cause of the ulcer, such as looking at the nearby teeth to see if there is a sharp and unsmooth gap. If there is such a situation, take your baby to the hospital’s stomatology department so that the doctor can deal with it. Second, pay attention to your diet and do not give your baby sour, spicy or salty food, otherwise your baby’s ulcer will be more painful. Give your baby a liquid diet to reduce the pain and also help the ulcer heal. Third, divert attention, care more about the baby, make the baby happy, take the baby to do games, divert his attention, create a relaxed and happy living environment for the baby. Also eat more fruits to replenish vitamins, such as apples, pears, peaches, watermelon and other vitamin-rich foods.