Bad breath (halitosis) can be inconvenient and embarrassing. Several factors cause bad breath: gum disease, food, tobacco, certain medical conditions, etc. For healthy people, the main reason for bad breath is the accumulation of microbacteria on the tongue. Studies show that it is possible to reduce halitosis of about 70% is you brush the back of your tongue. However, it is important to speak to your dentist if you have persisting bad breath because many factors can cause it and it is important to have the right diagnosis.