Bleeding bad breath from teeth may be chronic periodontitis or pulpitis, apical periodontitis, bacteria fermentation and inflammation in the mouth cause bleeding bad breath. 1. Chronic periodontitis. Chronic periodontitis when the gums are red, swollen and easy to bleed, bleeding is easily confused with bleeding teeth, long-term inflammation of the gums have different liquid exudation, in the role of oral bacteria, will lead to bad breath. 2. Pulpitis and periapical inflammation. Bleeding teeth and bad breath may also be the emergence of pulpitis or periapical inflammation, tooth decay up to the pulp cavity, causing pulp inflammation and necrosis and bleeding, due to the presence of carious cavities, food debris may be embedded in the cavity, fermentation and odor. Bleeding teeth and bad breath will affect oral health, it is recommended to go to the hospital in time to check the cause of timely treatment.