The causes of bad breath in girls may be as follows: first, unhealthy habits, such as not to develop a regular, healthy habit of brushing teeth, brushing should normally be once in the morning and once in the evening, each time ten minutes, if there is oral disease, you need to increase the number of times and time to brush your teeth. Second, girls with bad breath may also be due to eating foods that cause bad breath, such as garlic. Third, if there are digestive system diseases, may also lead to the occurrence of bad breath, such as oral diseases (gum, dental diseases, etc.), stomach diseases, liver diseases, esophageal diseases, etc. may cause bad breath, need to improve the relevant laboratory tests and examinations to further clarify the diagnosis, and then targeted treatment.