The tooth is connected to more nerves and is highly sensitive, so the slightest uncomfortable stimulus will pull on the nerves, resulting in toothache symptoms. There are many causes of toothache, which can be judged by toothache pattern and clinical manifestations. 1.Toothache caused by acute pulpitis: this kind of toothache often has obvious etiology, such as tooth decay, cervical wedge-shaped defect, cryptic fracture, trauma and so on. The pain pattern is spontaneous and paroxysmal pain, aggravated by temperature stimulation, accompanied by hemifacial pain, which cannot be localized, and attacks or aggravates at night, sometimes accompanied by mild percussion pain. 2, trigeminal neuralgia caused by toothache: atypical trigeminal neuralgia early manifested as individual toothache, pain is obvious when eating, talking or brushing teeth, the nature of pain is sharp pain, electric shock-like, knife-like, needle-like pain, lasting for a few seconds, pain is unbearable, accurate location, sometimes radiating, relieved at night, ranging from several to dozens of episodes per day. 3, toothache caused by maxillary sinusitis: because the roots of the maxillary teeth in the mouth are closer to the bottom of the maxillary sinus in the nasal cavity, maxillary sinusitis often causes pain in the maxillary molars as well as the premolar teeth, the pain is lighter in the morning, aggravated in the afternoon or after sitting for a long time, there is a history of cold before the onset, and most patients do not have any damage to their teeth.