Swelling on the left side of the face or jaw

Pain with a tooth, bad taste, gum tenderness, or trouble opening the mouth can point to a dental infection. Tenderness near the ear or under the jaw that worsens while eating may involve a salivary gland. A blocked nose, facial pressure, or recent cold can accompany sinus or upper-airway inflammation. A small tender lump under the jaw may be a nearby lymph node responding to infection.

A new medication, food, or insect exposure can cause allergic swelling. Fever, spreading redness, severe pain, or swelling around the eye needs prompt review. The location and speed of change are more useful than the side alone.

Note when the swelling started, whether it is enlarging, and whether eating, lying down, or touching it changes the discomfort. Use a cool compress for short periods and keep the head raised. Do not squeeze a lump, place heat on a suspected dental infection, or take leftover antibiotics. Arrange dental or medical assessment if pain, fever, discharge, or swelling persists.

Call emergency services for swelling of the lips, tongue, or throat, noisy breathing, difficulty swallowing saliva, or faintness. Seek urgent same-day care for rapidly spreading swelling, high fever, severe tooth pain, confusion, inability to open the mouth, or swelling near the eye. These signs can indicate an infection or allergic reaction that needs treatment quickly.

Ask: Does this look dental, salivary, skin-related, or like a lymph node? Do I need a dental examination or imaging? Which pain medicines are safe for me? What changes should make me seek emergency help?