Do you know someone with exceptionally bad breath? Do people back away from you during conversations? If proper brushing and flossing don’t make a difference then halitosis may be to blame, but what causes it? Any number of health problems can cause halitosis, but the first place to start looking is in your mouth. Tooth decay, heavy plaque build up and xerostomia can all contribute to halitosis. If your dentist gives you the all clear, then you should see your primary care physician to figure out what could be causing your halitosis. You may have a serious health issue that you didn’t previously know about.