Pain on one side of the face can be caused by trigeminal neuralgia, intracranial lesions, oral diseases and other factors. 1. Trigeminal neuralgia: it can be complicated by hemifacial spasm. Atypical facial pain can also occur in the innervated area of the trigeminal nerve, and the duration of the attack is always longer than a few seconds, usually several minutes, or persistent pain. 2. Intracranial lesions: Occupational lesions, especially in the area of the pontine cerebellum, can stimulate the corresponding nerves and produce symptoms of facial pain. This kind of pain is more intense, sometimes accompanied by tinnitus and hearing loss and other symptoms. 3. Oral disease: Acute pulpitis, apical periodontitis, wisdom teeth, peri-coronitis and other dental diseases in addition to causing toothache, may also appear head and face pain. If apical periodontitis and other infections in the intermaxillary space, there will be symptoms of facial pain, and patients usually have severe paroxysmal or persistent toothache at the same time. Pain on one side of the face may also be seen in other diseases, it is recommended to go to the hospital to clarify the cause of the disease, under the guidance of the doctor for treatment.