Facial paralysis may be caused by cold, trauma, infection and other reasons. 1. Exposure to cold: most patients have been stimulated by cold water and cold wind before the onset of the disease. At this time, the resistance of the human body is at its lowest point, and after encountering the cold air, the neurovascular spasm phenomenon, which will form the nerve edema, ischemia, and lead to facial paralysis. 2. Trauma: mostly seen in patients with craniocerebral injury and fracture, the primary damage of fracture to the nerve and the compression cut caused by the fracture will lead to tearing and contusion of the nerve. Fractures can also cause edema and ischemia of the nerve, leading to facial paralysis. 3. Infection: Commonly caused by herpes zoster virus infection, one side of peripheral facial paralysis is accompanied by herpes in the auricle, and will feel severe pain in the ear, resulting in damage to the facial nerve, which leads to the symptoms of peripheral facial paralysis. It is recommended that patients go to a regular hospital for a detailed examination to identify the cause of the disease and carry out appropriate treatment.