Tinnitus in the left ear at night, clinically, there are the following diseases may be. 1, neurogenic tinnitus, this situation is the most common in the clinic, may be related to the patient’s poor quality of sleep at night, insomnia, anxiety, depression and other adverse factors. The cause of this condition may be the inner ear membrane labyrinth accumulation of water, inner ear hair cell damage, inner ear vasospasm, inner ear vascular microthrombosis and so on caused by the inner ear blood supply and oxygen supply is insufficient, so that tinnitus neurological tinnitus, manifested as a high-pitched, shrill sound. 2, some patients have secretory otitis media, suppurative otitis media induced tinnitus, this kind of tinnitus and the inflammation of the inner ear canal, and other factors. 3, some patients have vascular pulsatile tinnitus, and so on. Patients have vascular tinnitus, may be related to vascular anatomical deformities or blood flow changes and other factors, common clinical diseases are jugular vein bulboma, arteriovenous fistula, severe hyperthyroidism, severe anemia. If the tinnitus has seriously affected sleep or hearing loss, ear pus, etc., it is recommended to go to a regular hospital otorhinolaryngology as soon as possible.