There are various causes of facial palsy, which can be divided into central facial neuritis and peripheral facial neuritis according to the site of damage. Central facial palsy lesions are located above the facial nucleus to the cerebral cortex and are usually caused by cerebrovascular disease, intracranial tumors, and traumatic brain injury. Peripheral facial palsy lesions occur in the facial nucleus and facial nerve. Common causes of peripheral facial palsy are: infectious lesions, mostly caused by viral infections; otogenic diseases, such as otitis media; autoimmune reactions; tumors; metabolic disorders, such as diabetes mellitus and vitamin deficiency; common types include: 1. Idiopathic facial nerve palsy: the main type of facial nerve palsy is idiopathic facial nerve palsy, often called Bell’s palsy, which accounts for 60% to 75% of all facial nerve palsy cases . The most common is unilateral facial nerve palsy. The degree of facial nerve palsy can be complete or incomplete, and this diagnosis is considered after other etiologies are ruled out. 2, infection: Infection is the 2nd most common cause of facial nerve palsy. Common causes of infection include viruses, spirochetes and bacteria. This type of facial nerve palsy accounts for 12% of all facial nerve palsy. 3, facial nerve palsy can also be secondary to middle ear infections: middle ear infections that are not treated in a timely manner can cause facial nerve palsy. 4, tumors: tumors are second only to infection as a common cause, about 5% of facial nerve palsy patients caused by tumors. These tumors include auditory neuroma, parotid adenoma, primary cholesteatoma and jugular bulb tumor. In unusual cases, both the tumor itself and surgical removal of the tumor can cause facial nerve palsy. In conclusion, a variety of causes can cause the symptoms of facial palsy. It is important to first distinguish between peripheral facial palsy and central facial palsy, and then the cause of the lesion, which should be promptly diagnosed at a regular medical institution and specialist.