Facial neuritis, also known as idiopathic facial nerve palsy, is a peripheral facial palsy caused by nonspecific inflammation of the facial nerve in the stoma. The etiology is unknown, but the triggering factors may be wind chill, viral infection, and autonomic instability that cause local neurotrophic vasospasm, resulting in ischemic edema of the nerve. The early pathological changes of facial neuritis are edema and demyelination of the nerve, and in severe cases, axonal degeneration may occur. The clinical manifestations are: 1. Acute onset, symptoms may peak within hours or 1-3 days. 2. The disease can develop at any age, with slightly more males. The disease may be accompanied by pain in the mastoid area behind the ear, in the ear or in the angle of the jaw, complete paralysis of the facial expression muscles on one side, disappearance of the frontal lines, inability to frown, enlargement of the eye fissure, inability to close the eyelid or incomplete closure, and exposure of the white sclera when the eye is closed. The nasolabial folds on the affected side become shallow, the corners of the mouth droop, and the corners of the mouth are skewed to the healthy side when the teeth are shown. The paralysis of the orbicularis oris muscle causes air leakage during puffing and whistling. Due to the paralysis of the buccal muscle, food is easily retained between the teeth and cheeks on the affected side. The taste fibers from the geniculate ganglion travel in the facial nerve canal, and then separate from the facial nerve to form the bulbar nerve, which later joins the lingual nerve to innervate the taste sensation in front of the tongue. If the lesion is above the facial nerve, there can be ipsilateral loss of prelingual taste; if the stapedius muscle branch is damaged, there can be ipsilateral loss of prelingual taste and auditory hypersensitivity; if the lesion is in the geniculate ganglion, in addition to peripheral facial palsy, prelingual taste disorder and auditory hypersensitivity, there is also pain in the affected mastoid area, loss of sensation in the auricle and external auditory canal, and herpes in the external auditory canal or tympanic membrane.