Swelling of the lips for no reason is not excepted as a result of allergic diseases. Some patients can be allergic after eating special foods, including seafood, or fruits, such as durian or dragon fruit. The typical manifestation is edema of the lips and mouth, and even cyanosis and local bruising, and in severe cases, tracheal spasm and labored breathing should be treated promptly. In addition, local soft tissue infection, mostly after burns, or local gingivitis, oral infection, the patient will also have local pain and fever, swallowing food will lead to aggravation of symptoms, so should also be actively treated. You should also pay attention to oral hygiene and rinse your mouth after each meal, or choose to use warm salt water to rinse your mouth every day.