1, Bell facial palsy: the diagnosis is mainly exclusionary, and the current diagnostic criteria are: (1) complete or incomplete paralysis of facial expression muscles; (2) sudden onset; (3) exclusion of diseases of the central nervous system, posterior cranial fossa, ear, and parotid gland. 2. Ramsay Hunt syndrome: It is a polyneuropathy caused by varicella-zoster virus and manifests as sudden peripheral facial paralysis; pain in the affected ear, herpes of the tympanic membrane, external auditory canal, and auricle; possible hearing loss, auditory hypersensitivity, tinnitus, and vertigo. Other systemic manifestations include fever, herpes of the mouth and lips, swollen lymph nodes, Horner’s syndrome, and dullness of skin sensation in the neck. Among them, “facial palsy, otalgia and herpes” are considered as the triad of Ramsay Hunt syndrome. Compared with Bell’s facial palsy, Ramsay Hunt syndrome has severe facial palsy and a poorer prognosis. It is important to note that Ramsay Hunt syndrome is easily confused with Bell’s palsy when herpes appears later than facial palsy. 3. Acute and chronic middle ear mastoiditis: 2-5% of these patients may develop facial palsy due to the invasion of the nerve by inflammation and the compression of the nerve by cholesteatoma or sarcoid. The diagnosis can be made based on history, physical examination, audiology and imaging. 4. Traumatic facial palsy (including surgery): depending on the degree and location of injury, it may be immediate or delayed, complete or incomplete facial nerve palsy, and the diagnosis can be clarified by medical history and imaging examination. 5. Benign and malignant tumors of the pontocerebellar horn, temporal bone, lateral skull base, and parotid gland can cause facial nerve palsy, and the following features of facial palsy should be highly suspected: (1) progressive facial nerve palsy for more than 3 weeks; (2) no signs of recovery of facial nerve function within 6 months; (3) facial muscle spasm; (4) prolonged ear and facial pain; (5) concomitant other cranial nerve dysfunction; (6) ipsilateral (6) Recurrent facial palsy; (7) Normal function of individual facial nerve branches. Facial nerve tumors are mainly nerve sheath tumors and neurofibromas, with a ratio of 10:1. 75% of patients develop facial palsy, mostly as progressive facial nerve palsy, and a few have sudden onset, which may be accompanied by deafness, tinnitus, vertigo, and facial muscle spasm. In addition to deafness, tinnitus, and vertigo, a few patients with auditory neuroma may also develop facial nerve palsy. Benign parotid tumors rarely occur facial paralysis, while malignant parotid tumors can cause facial paralysis, which is mostly slowly progressive. Congenital cholesteatoma and jugular venous bulbar tumor can also cause facial palsy. Facial nerve palsy caused by the above tumors can be clearly diagnosed by imaging. Lyme disease: It is a tick-borne infectious disease with multi-system involvement. The pathogen is Burkholderia pallidum, which mainly manifests as wandering skin erythema, heart block, joint swelling, meningitis, etc. Facial nerve palsy occurs in 10% of patients, and 1/4 of them have bilateral palsy. The diagnosis can be clarified by contact history, serum pathogen testing and anti-Borrelia burgdorferi antibody testing. 7. Melkersson-Rosenthal syndrome: mostly disseminated cases, but also reported familially. The main manifestations are swelling of the mouth and lips, tongue folds and facial nerve palsy, which manifests as sudden peripheral facial nerve palsy, either unilateral or bilateral, and often recurrent. 8, Grinbaric syndrome: peripheral facial palsy may appear, mostly bilateral, with symmetrical limb paresis and brain crest fluid protein-cell separation phenomenon as its characteristic manifestations.