Swollen Lip and Face on One Side: What to Know

Swelling on one side may reflect a tooth or gum infection, a bite or sting, a blocked salivary gland, skin inflammation, recent dental work, or an allergic process. Pain, warmth, redness, a bad taste, tooth sensitivity, or fever makes a dental or infectious source more concerning. Itching, hives, or rapid onset after food, medicine, or a product can occur with angioedema, a deeper type of swelling described in [Angioedema](/conditions/angioedema/). Facial drooping, arm weakness, speech trouble, or new confusion is not typical simple lip swelling and needs emergency assessment.

Note when the swelling began, whether it is enlarging, and any new foods, medicines, products, bites, injections, dental procedures, or injuries. Avoid suspected triggers and do not squeeze, lance, or massage the swollen area. A cool cloth may ease discomfort if the skin is intact. Do not place aspirin or harsh chemicals on the gum or lip. If tooth pain, fever, or drainage is present, arrange prompt dental or medical assessment rather than waiting for home care to resolve the cause.

Get emergency help for tongue or throat swelling, breathing difficulty, trouble swallowing, faintness, rapidly increasing swelling, facial drooping, weakness, speech changes, or confusion. Seek prompt same-day care for fever, severe tooth or facial pain, spreading redness, pus, eye swelling, or difficulty opening the mouth. A clinician may need to examine the mouth, teeth, skin, nerves, and airway to identify the source.

Ask whether the swelling points to a dental, skin, allergic, or salivary cause, which examination is needed, and which changes should send you straight to emergency care.