Causes of facial swelling on one side of the face

A tooth or skin infection can cause focal pain, warmth, redness, tenderness, or pus. Cellulitis may spread through nearby skin and can come with fever. Sinusitis may cause swelling or pressure near the cheek or eye with congestion and thick nasal discharge. Angioedema can affect one side or both sides and may involve the lips or eyelids, especially after a food, medicine, or insect exposure. Chronic kidney disease more often causes swelling in several areas rather than a single painful spot. Anaphylaxis is defined by a rapid allergic reaction with breathing, throat, circulation, or widespread symptoms; facial swelling alone cannot establish that diagnosis.

Check the area for redness, warmth, tenderness, dental pain, rash, nasal symptoms, or a recent bite or injury. Note when it began and whether it is spreading. Arrange same-day medical or dental advice for painful, warm, red, or rapidly enlarging swelling. Do not squeeze a lump or apply unknown creams near the eye. Keep a record of new foods and medicines if the episode resembles an allergy.

Call emergency services for tongue or throat swelling, trouble breathing, wheezing, faintness, or rapidly progressing swelling. Seek urgent assessment for swelling around the eye with vision change, severe pain, high fever, confusion, difficulty swallowing, or inability to open the mouth. These signs can indicate a spreading infection or a serious allergic reaction.

Ask whether the location and associated symptoms point toward dental infection, cellulitis, sinusitis, allergy, or angioedema, and whether you need examination, treatment, or emergency precautions.