Cold toothache may be caused by dentin allergy, periodontitis, dental caries, etc., and can be treated by desensitization, medication and filling treatment. 1. Dentin allergy: It may be caused by excessive tooth wear, wedge-shaped defects, etc. Patients can improve the treatment by desensitization and filling the defects. 2. Periodontitis: Periodontitis is an inflammatory disease that occurs in the periodontal tissues, due to dental calculus, plaque long-term stimulation caused by alveolar bone resorption, gingival recession, root exposure, etc., a cold tooth will be sore, patients can be relieved by periodontal therapy. 3. Dental caries: when the cavity of dental caries is close to the pulp of the teeth, will be stimulated by the cold and produce toothache phenomenon, this time can be removed through the decayed tooth tissue, filling the way to treatment. Cold toothache suggests that patients go to the regular hospital in a timely manner, follow the doctor’s instructions to improve the relevant examination and treatment.