What Causes Bad Breath Odor? Even if you can't explain what bad breath is, you definitely know what it smells like. Bad breath's clinical term is halitosis, meaning breath containing a unpleasant bad odor. Although may people find the subject matter humorous, a quarter of people seeking treatment for this problem suffer from halitophobia, a condition where a patient has an over exaggerated concern of having bad breath odor. This affects approximately almost 1% of the adult population. This problem has led to many scientific studies on this issue. The foul odor from the mouth can be caused by various reasons based on various factors. For most people (statistically at 80%), bad breath can be caused by bacteria living inside their mouth, concentrated mostly on the back of the tongue. The warm and moist environment of the mouth encourages the growth of bacteria. This condition is often referred to as "morning breath" from the average person. Morning breath or morning mouth occurs when your mouth produces less saliva at night so dead cells will attach to your tongue and be eaten by bacteria which excretes substances that lead to bad odor. Also, having poor oral hygiene such as not brushing teeth or rinsing your mouth regularly will lead you to bad breath. Eating specific foods such as garlic or onions or drinking coffee and smoking can make your breath smelly as well. However, bad breath isn't always a benign condition. It may also be a sign of an oral health problem. For example, a decaying tooth or oral infections can cause this health issue. Furthermore, more serious problems such as liver disease, diabetes, and lung disease can also cause bad breath. So if you do have this problem and simple remedies do not solve it, it is best to consult a doctor who can better help you find the cause and a solution to this problem.