A tooth that hurts to the nerve needs a root canal for relief. Tooth pain to the nerve is what is medically known as pulpitis, which usually occurs when tooth decay infects the pulp. The pulp cells degenerate and ooze out, the pressure in the pulp cavity increases, paroxysmal severe pain, hot and cold pain, night pain, the use of pain medication can not be relieved, the pain can not be localized, and can be dispersed to the head. To relieve the pain, root canal therapy is performed under local anesthesia. Firstly, the pulp cavity is opened with a dental drill, decompression and drainage is carried out, the pain is relieved, and then the inflamed pulp in the root canal is cleaned out and the root canal system is sealed tightly with medication, and the root canal therapy is completed to preserve the affected tooth. Tooth pain to the nerve need to promptly seek medical attention, under the guidance of the doctor for examination and treatment, to avoid delays in the condition.