Bad breath is serious out of breath are stinky to first determine the source of bad breath, exogenous bad breath need to clean oral hygiene, endogenous bad breath need to be based on the cause of the drug or other treatment. 1. Exogenous bad breath. The human body mouth and nose are connected, when the degree of halitosis is serious, there will be nasal exhalation of gas is also stinky, if the food residues in the mouth caused by fermentation, you need to brush your teeth carefully, while cleaning the back of the tongue with floss to clean the gap between the teeth. If the accumulation of tartar triggered gingivitis, periodontitis, periodontal treatment is needed to eliminate gum inflammation. If the bad breath is caused by caries, it is necessary to remove the decayed material and then fill with resin, and if it is caused by pulpitis or periapical periodontitis, it is also necessary to carry out root canal treatment and then fill with resin. 2. Endogenous bad breath. When eating certain irritating foods, the substances in them into the bloodstream will also transmit the odor through the lungs, it is recommended to eat less irritating odor of food, may also be caused by diseases, such as periodontitis should be periodontal sequence treatment; respiratory diseases such as bronchitis or gastric diseases such as gastric ulcer, esophagitis, need to treat the internal medicine physician for various systemic diseases. Severe bad breath can affect your life and mental health, so you need to go to the hospital as soon as possible.