Left ear pain is a symptom of a number of common diseases, such as: auricular diseases, otitis externa, otitis media, ear canal foreign body secondary infection. 1. Auricular diseases: left auricular skin folliculitis, soft tissue infections, eczema, trauma, mosquito bites, etc. can cause symptoms of left ear pain. 2. Otitis externa: left otitis externa, inflammatory stimulation will cause congestion and swelling of the skin of the external auditory canal, which will lead to left ear pain. 3. Acute otitis media: left acute otitis media caused by bacterial infection, causing acute congestion of the mucous membrane of the tympanic chamber, or even pus, perforation of the tympanic membrane, so causing left ear pain. 4. Foreign body secondary infection in the ear canal: for example, cerumen in the left ear, cholesteatoma cyst in the external auditory canal, etc., swelling after water intake and even secondary infection can also cause symptoms of left ear pain. There may be other reasons for left ear pain, so you need to go to the hospital for further examination to clarify the cause of the problem and follow the doctor’s instructions.