When a patient suddenly has symptoms of a crooked mouth, two causes should be considered: the first is acute cerebrovascular disease, and the second is peripheral facial neuritis. For either cause, the patient should immediately consult a hospital for examination and identification by a doctor. If acute cerebrovascular disease is considered, immediate treatment must be given, such as transient ischemic attack or cerebral infarction, and patients should be given a regimen of thrombolysis, fibrin-lowering, anticoagulation, and antiplatelet aggregation. At the same time, treatment of cerebral protection should be given to save the patient’s ischemic semidark zone and reduce the symptoms of neurological deficits, so that the patient’s symptoms of a crooked mouth can be restored. If peripheral facial neuritis is considered to be the cause, antiviral drugs or hormones should be used after diagnosis to reduce the edema of the facial nerve, which is beneficial to the recovery treatment of patients at a later stage.