If the bad breath is mild, you can’t smell it, but if it’s severe, you may be able to smell it. Halitosis is related to many factors, may be caused by oral diseases, such as oral ulcers, gingivitis and other diseases may lead to bad breath symptoms, but also may be related to gastrointestinal diseases, such as gastritis, gastric ulcers, duodenal ulcers, gastroesophageal reflux and other diseases may also produce bad breath. If the bad breath is mild, you can adjust your diet and pay attention to rest, but if the bad breath is more serious, it is best to use medication in time, such as oxalic acid stomach pills, patchouli stomach capsule, etc., to avoid aggravation of the symptoms. Or seek medical treatment as soon as possible, periodontal cleaning, eliminate gum inflammation.