lip swollen
Swollen lips. Swollen lips, or lip oedema, is when one or both lips enlarge or distend beyond their normal size. This swelling is caused by a build-up of fluid, or inflammation inside the lip tissue. It can have many causes, including injury, illness, certain medicines or allergies. Swollen lips can be a sign of anaphylaxis â a severe allergic reaction â which requires immediate medical attention.