Facial neuritis: also known as idiopathic facial nerve palsy or Bell’s palsy, is the most common facial nerve disorder that may result in peripheral facial palsy due to nonspecific inflammation of the facial nerve within the stalk mammary foramen. It can develop at any age and is not gender- or time-specific. Etiology and mechanism: The etiology is not fully elucidated. The bony facial nerve canal can only accommodate the passage of the facial nerve, and once the facial nerve becomes ischemic and edematous, it inevitably leads to facial nerve damage. The causative factors can be wind and cold, viral infection and autonomic instability, and local neurotrophic vascular spasm leading to nerve ischemia and edema. Clinical manifestations: The disease usually has an acute onset, with facial nerve palsy reaching severity within 48 hours in about half of the cases and peaking within 5 days in all cases. Most patients tend to suddenly notice the inability to move one cheek and the crookedness of the mouth when washing the face or rinsing the mouth in the early morning. The forehead wrinkles disappear, the eye fissures widen, the nasolabial folds flatten, the corners of the mouth droop, and the corners of the mouth are skewed to the healthy side when the teeth are exposed. When the cheeks are puffed and whistled, the affected side of the mouth leaks air because the lips cannot be closed. When eating, food residues are often retained in the gap between the teeth and cheeks on the affected side, and saliva often flows down from that side. At the beginning of the disease, there is mostly pain around the ear; it may be accompanied by loss of taste in the first 2/3 of the tongue on the affected side; hearing hypersensitivity, hearing loss, etc. Diagnosis: The diagnosis of idiopathic signs and symptoms is generally not difficult. Differential diagnosis: Grimballi syndrome; otogenic facial nerve palsy; Lyme neuropathy, usually with other cerebral nerve involvement; posterior cranial fossa tumor or meningitis; central facial palsy. Ancillary tests: cerebrospinal fluid examination reveals mild elevation of single nucleated cells; Gd-enhanced MRI reveals Bell’s palsy of the facial nerve. Electromyography can effectively identify temporary nerve conduction disorder from pathological blockage. Treatment: The principle is to improve local blood circulation, reduce facial nerve edema, relieve nerve compression, and promote nerve function recovery.