Deafness can be categorized into conductive deafness, sensorineural deafness and mixed deafness according to the different causes. Mecobalamin is a kind of drug that has the effect of nourishing the nerves, so it may be effective for sensorineural deafness and mixed deafness related to neurological factors, but it is generally ineffective for conductive deafness. 1. Conductive deafness: Conductive deafness is caused by structural and functional disorders of the sound conduction pathway. Secretory otitis media, blockage of the external auditory canal and otosclerosis are common causes. There is no connection between conductive deafness and neuropathy, so the use of methylcobalamin tablets is usually ineffective. 2. Sensorineural deafness: Impaired sound perception and nerve impulse transmission can cause sensorineural deafness. As methylcobalamin tablets are a kind of drugs used in the treatment of peripheral neuropathy, it can promote the function of nerve axon transportation and axon regeneration, and has the effect of nourishing the nerves, so it has a certain effect on the diseased nerves, which can assist in the treatment of sensorineural deafness. 3. Mixed deafness: mixed deafness refers to the sound transmission system and the sensorineural system part of the ear are abnormal damage, and methylcobalamin tablets can be used to promote the repair of the sensorineural system lesions, mixed deafness can play a certain therapeutic effect. The use of methylcobalamin tablets is occasionally associated with adverse reactions such as nausea, vomiting, loss of appetite as well as diarrhea; it must be contraindicated for those who are allergic to methylcobalamin tablets; and there is no need to continue to take the drug if it is ineffective for more than one month of continuous use. Whether deaf people can take methylcobalamin tablets should be evaluated by a medical professional, and self-medication is not recommended.