Teeth are not bad feeling nerve pain considerations with dentin allergy, cracked teeth and other factors. 1. Dentin allergy, if there is dentin allergy, the degree of sensitivity of the teeth increased, when the teeth are stimulated by the nerve may appear very painful symptoms. 2. Cracked teeth, cracked teeth, cold and hot stimulation caused by the symptoms of pulpitis, pain will occur. After the emergence of pulpitis, the pressure of the pulp cavity rises, may cause stimulation of the pulp tissue, so the nerve will appear very painful symptoms, although the tooth is not broken, but the inflammation invades the pulp will still have pain symptoms. If you feel a lot of nerve pain, it is recommended to consult a doctor in time for dental radiography to determine the changes in the periodontal tissues and then symptomatic treatment to avoid affecting the patient’s normal life.