Bad breath occurs after getting up. First, due to the oral cavity bacteria will reproduce more at night, swallowing and chewing will be weaker, the bacteria reproduce faster, the formation of a large number of secretions, these substances in the wake up will be secreted to the outside with the breath, bad breath occurs. Secondly, if you eat spicy stimulating food or with flavor before going to bed, such as leeks and other foods, will also make bad breath after getting up, it is possible that the gastrointestinal gases appear in the mouth, with the respiratory discharge to the outside of the body, bad breath. In addition to this, if there are caries in the mouth, residual tooth roots are not extracted, there will be a lot of bacteria itself, if there is gingivitis, periodontitis, the presence of dental calculus around the teeth, bacteria are also very much, after a night of fermentation, bacteria will become particularly high, bad breath. Different treatment measures can be taken for different kinds of bad breath.