Suddenly having a crooked face and mouth may be caused by facial neuritis, cerebrovascular disease or epileptic seizures. 1. Facial neuritis: usually caused by cold stimulation or viral infection, which can lead to lesions of the facial nerve, resulting in paralysis of the expression muscles on the affected side, manifesting as a sudden crooked face and mouth, which may also be accompanied by the widening of the eye slit and disappearance of frontal lines. 2. Cerebrovascular disease: commonly seen in acute cerebral infarction or acute cerebral hemorrhage, which may lead to local cerebral nerve damage, causing cerebral dysfunction, which may show central nervous system paralysis, and may result in a sudden distorted face and mouth, and may be accompanied by unfavorable speech, numbness of limbs and other symptoms. 3. Epileptic seizure: when the epileptic seizure, the patient may show symptoms of crooked face and mouth, may also be accompanied by generalized convulsions, foaming at the mouth, eyes hanging, etc., mainly due to the abnormal discharge of neurons in the brain. Suddenly, a crooked face and crooked mouth may also be caused by other reasons, so you should consult a doctor in time, and after completing the relevant examinations to clarify the cause of the disease, you will be guided by the doctor to carry out the treatment.