Otosclerosis is a lesion that occurs in the bony vagus capsule of the inner ear and is characterized by spongy degeneration and asymmetric, progressive hearing loss in both ears. The incidence of this disease is higher in Caucasians than in Blacks, Yellows, and North American natives. The cause of otosclerosis is still unclear, but it may be related to the following factors: 1, hereditary factors: some patients with otosclerosis have a family history, and it is believed that the disease is autosomal dominant or recessive. 2, viral factors: the onset of otosclerosis may be related to measles virus infection. Endocrine factors: The incidence of otosclerosis is high in women, and the symptoms are aggravated during pregnancy, so it is believed that the onset of otosclerosis is related to hormone levels. 4.Immune factors: Studies have shown that the level of autoantibodies in the serum of patients with otosclerosis is increased. If the lesion invades the vestibular window niche, the circumferential ligament and the stapes, the stapes activity will be limited to disappear, which is called stapedial otosclerosis. In the same case, both types can exist at the same time. Clinical manifestations】 1. Hearing loss: Slowly progressive, asymmetric hearing loss in both ears without obvious causes. The hearing loss is slowly progressive and asymmetrical in both ears without any obvious cause, and the self-talk is small due to enhanced self-hearing. In addition, patients have Wechsler’s mishearing, i.e., patients feel hearing improvement in noisy environment. 2.Tinnitus: About half of the patients have tinnitus, which is usually mild. 3.Vertigo: Patients with cochlear otosclerosis may develop vertigo, often manifesting as recurrent episodes of vertigo or balance disorders. 1. Otoscopic examination: The tympanic membrane is intact and the sign is normal. In some patients, a translucent red area in the upper posterior quadrant is visible, which is a reflection of mucosal congestion in the headland area, called Schwartze’s sign, suggesting that otosclerosis is in an active stage. 2. Audiological examination (1) Tuning fork examination: Weber’s test is biased toward the affected side or the heavy side, and Rinne’s test is greater in bone conduction than in air conduction. (2) Pure tone audiometry: The audiogram shows mild to moderate conductive deafness, and the degree of hearing loss is related to the stage of otosclerosis. There can be a 10-30 dB drop in bone conduction at 2 kHz, called the Cajal cut, which is caused by stapes fixation. (3) Tympanic chamber function examination: normal tympanogram and sound compliance value, stapedius muscle reflex cannot be elicited, good pharyngeal canal function. In advanced otosclerosis cases, thickening of the stapes floor and irregularity of the bone shadow of the vagus capsule can be observed. Diagnosis】 Stapedial otosclerosis: Progressive asymmetric conductive deafness and low-pitch tinnitus in both ears without any cause, normal tympanic membrane, good eustachian tube function, pure tone bone conduction hearing curve with Carhart’s cut, normal tympanic conduction pattern, and family history. Snail otosclerosis: Progressive binaural sensorineural deafness with no apparent reason consistent with age, intact tympanic membrane, decreased audiogram for both air and bone conduction but 15dB to 20dB difference in low frequency bone and air conduction hearing threshold, type A tympanic chamber conductance map, family history. Treatment】 The first choice is surgery, and the main surgical method is stapedial fundoplication. For those who have contraindications to surgery or refuse surgical treatment, they can wear hearing aids or use sodium fluoride medication.