Causes of swelling and pain below the ear include mumps, peri-auricular lymphadenitis, and temporomandibular arthritis. 1. Mumps: When the virus invades the parotid gland, it can lead to acute respiratory infections. Swelling and pain below the earlobe and swelling of the parotid gland appear. Pain also occurs when opening the mouth or chewing. 2. Peri-auricular lymphadenitis: When there is inflammation in the ear, such as otitis media. It can lead to symptoms of swelling and pain in the lymph nodes around the ear. When you touch the swollen lymph nodes, their surface is smooth and movable. 3. Temporomandibular arthritis: When temporomandibular joint occurs, it can cause pain in the muscles around the jaw joint, because the ear is adjacent to the temporomandibular joint and connected through the nerve. Therefore, symptoms of pain under the ear can occur. When swelling and pain below the ear, it is recommended to go to the hospital as soon as possible to clarify the cause of the disease, so as to facilitate targeted treatment. At the same time, it is recommended to eat a light diet and avoid spicy and irritating food, so as not to aggravate the symptoms.