Tinnitus in the left ear may be caused by diseases of the ear itself, systemic diseases and so on. 1. Diseases of the ear itself: e.g. otosclerosis, cerumen impaction, non-purulent or purulent otitis media, Meniere’s disease, sudden deafness, acoustic neuroma, etc. 2. Systemic diseases: such as hypertension, arteriosclerosis, anemia, leukemia, diabetes mellitus, nephropathy, poisoning, hyperlipidemia and so on. 3. Other factors: such as excessive work or life stress, emotional disorders, sleep disorders, irregular work and rest or eating habits, long-term noise environment. There are many causes of tinnitus, which need to be judged with other tests. If you have tinnitus in your left ear, it is recommended that you go to the hospital in time for diagnosis and treatment.