Swollen upper lips can develop due to allergic reactions, injuries, or medication side effects. However, they can also stem from an infection, Crohn’s disease, and other underlying causes. This ...

Swollen lips may be caused by allergic reactions, injuries, chapping or sunburn, infections, and cysts called mucoceles. The swelling comes from either inflammation or built-up fluid under the skin.

A person’s lips can swell on one side for several reasons, such as allergic reactions, injuries, or long-term medical conditions. Keep reading to explore why a person’s lip may swell on one side, and ...