1. Toothache Toothache is also a very painful disease, sometimes especially at the beginning of the disease, often to the oral cavity, was misdiagnosed as toothache, many patients will be extracted teeth, or even all the teeth on the affected side, but the pain still can not be relieved. Generally, toothache is characterized by persistent dull pain or throbbing pain, confined to the gum area, not radiating to other parts, no facial skin allergy area, not aggravated by external factors, but patients dare not chew with their teeth, the application of X-ray examination or CT examination can clarify toothache. 2.Trigeminal neuritis Trigeminal neuritis can be caused by acute maxillary sinusitis, influenza, frontal sinusitis, mandibular osteomyelitis, diabetes, syphilis, typhoid, alcohol poisoning, lead poisoning and food poisoning and other diseases. Most often there is a history of inflammatory infection with a short medical history, pain is persistent, local compression of the infected branch may increase the pain, and on examination there is hyperalgesia or hypersensitivity of the affected trigeminal nerve subdivision. It may be accompanied by motor disorders. 3.Intermediate neuralgia Patients with intermediate neuralgia have the following characteristics: (1) Nature of pain: episodic burning pain, long duration, several hours, or several minutes in short cases. (2) Pain site: mainly located in the external auditory canal, auricle and mastoid process on one side, and in severe cases, it may radiate to the same side, lateral tongue, pharynx and occipital area. (3) Concomitant symptoms: localized herpes zoster, peripheral facial palsy, taste and hearing changes may also be present. 4.Pterygopalatine neuralgia The cause of this condition is unknown, but most people believe that paranasal sinusitis invades the pterygopalatine ganglion and causes it. (1) Pain site: deep parts of the face such as the nasal cavity, pterygoid sinus, septal sinus, hard palate, gingiva and orbit in the distribution area of the pterygopalatine ganglion branches. The pain is more widespread. (2) Nature of pain: the pain is burning or drill-like and relatively intense, with persistent or paroxysmal exacerbation or periodic recurrent attacks, which usually last for several minutes to several hours. It is accompanied by swelling of the nasal mucosa on the affected side, nasal congestion, and increased nasal discharge, which is mostly plasma or mucus in nature. It may be accompanied by tinnitus, deafness, watery eyes, photophobia and burning and tingling sensation in the skin of the jaw. The pain may occur from the teeth, nasal roots, orbits and eyes, and then extend to the gums, forehead, ears and mastoid region, all on one side. In severe cases, the pain radiates to the ipsilateral neck, shoulder and hand, and there may be pressure pain in the orbit. (3) Age of onset: often between 40 and 60 years old, with more women. (4) This disease can be diagnosed by doing pterygopalatine nerve closure with 1% procaine or surface anesthesia of pterygopalatine ganglion with 2%-4% bupivacaine via nasal cavity, which can make the pain relieved. Migraine is also called cluster headache, which is a clinical syndrome mainly characterized by vasodilation and contraction dysfunction of the head. The cause of migraine is complex and has not yet been fully elucidated. However, it is related to family, endocrine, allergic reaction and psychological factors. Clinical features: (1) It is common in adolescent females, and most of them have family history. (2) Triggering causes: Mostly triggered by fatigue, menstruation, emotional agitation, with aura before each attack, such as blurred vision, flashing light, dark spots, eye distention, hallucinations and partial blindness. The aura symptoms can last from several minutes to half an hour. (3) The nature of the pain is severe headache with throbbing pain, stabbing pain and tearing or swelling pain. Recurrent attacks, once a day or once every few weeks, months or even years. They are accompanied by nausea, vomiting, a feeling of stool, watery eyes, and a pale or flushed complexion. Fatigue and drowsiness after the attack. (4) On examination, the pulsation of the superficial temporal artery is significantly increased, and the pain may be relieved by compression. Application of antihistamines at the time of aura attack may relieve the symptoms. (5) Migraine also has common type and special type (oculomotor paralysis, ventral type, basilar artery type) migraine, all of which need to be differentiated. (6) Glossopharyngeal neuralgia This disease is divided into two categories: primary and secondary. It is a kind of paroxysmal severe pain in the distribution area of the glossopharyngeal nerve. The age of onset is more than 40 years old, and the nature of pain is similar to that of trigeminal neuralgia. The clinical manifestations have the following characteristics. (1) The etiology may be related to the compression of the posterior inferior cerebellar artery and vertebral artery into the nerve entry area. In addition, it can be caused by tumors, inflammation, cysts, nasopharyngeal tumors, or stromal hyperostosis at the cerebellopontine angle. (2) The pain site is at the root of the tongue, throat, tonsils, deep ear and posterior jaw of the affected side, sometimes with deep ear pain as the main manifestation. (3) The pain is sudden and stops suddenly, each attack lasts for a few seconds or tens of seconds, and rarely exceeds 2 min. It also resembles severe pain like stabbing, cutting, burning, tearing and electric shock. If the pain is secondary, it is long or persistent, the trigger and trigger point may not be obvious, and it is heavier at night. (4) The trigger is often pain induced by swallowing, chewing, talking, coughing, or yawning. (5) More than 50% have trigger points, mostly at the posterior pharyngeal wall, tonsillar hyoid root, etc., and a few at the external auditory canal. If it is secondary, the trigger point may not be obvious, while the symptoms of damage to the linguopharyngeal nerve, such as soft palate paralysis, loss of sensation or loss of sensation in the soft palate and pharynx, etc. (6) Other symptoms: swallowing often causes painful episodes, and although there is no pain between episodes, patients are afraid to eat or careful to enter some fluid juice for fear of inducing pain, and patients become wasted or even dehydrated due to little food and water intake, pharyngeal discomfort, and cardiac arrhythmia.