Severe halitosis may be caused by periodontitis, tonsillitis and other diseases, if it is caused by periodontitis, need to carry out perfect periodontal treatment, if it is caused by tonsillitis, feasible medication and surgical treatment, specific as follows. 1. Periodontitis: Porphyromonas gingivalis and Porphyromonas intermedia in periodontal pockets have the ability to produce odor, and the symptoms of bad breath can be relieved by perfect periodontal treatment, including gingival cleaning, subgingival scraping and root planing. 2. Tonsillitis: purulent tonsillitis, food debris and stones in the deep sockets can produce odor, antibiotic treatment can be used, such as amoxicillin, etc. For recurrent tonsillitis, surgical resection can be performed after the acute inflammation subsides. The above medications should be used under medical supervision. Severe bad breath may have other causes, such as digestive system diseases, it is recommended to go to the hospital in time, to clarify the cause of the disease and then targeted treatment.