Tinnitus in the left ear may be caused by physiological reasons such as lack of sleep and excessive stress, or it may be caused by cerumen impaction, otitis externa, purulent otitis media and so on. 1. Physiological causes: If the patient is overworked, nervous, stressed or sleep deprived, it is easy to cause tinnitus in the left ear, which is usually relieved in a short period of time through rest. 2. Cerumen impaction: It is a disease caused by cerumen gathering and blocking the external ear canal, if cerumen impaction occurs in the left ear, it will lead to tinnitus in the left ear. 3. Otitis externa: usually manifested as ear pain, tinnitus, ear stuffiness, and discharge of secretion in the ear, etc. If it is otitis externa in the left ear, there will be tinnitus only in the left ear, and it may be accompanied by fever, fatigue, and pressure pain on the ear screen. 4. Suppurative otitis media: If there is suppurative otitis media in the left ear, only tinnitus in the left ear will occur, accompanied by fever, dizziness and other symptoms. Patients with tinnitus in the left ear, there may be other reasons, such as auditory nerve disease, tumors, etc. If accompanied by other symptoms, should go to the hospital in a timely manner, to clarify the cause of the disease, under the guidance of the doctor reasonable treatment.