The halitosis is simply a bad breath problem for many people at one time or another. It was estimated that 40% of the population suffers from chronic bad breath at one time or another.
Many causes may be responsible for bad breath include: 
An oral hygiene inadequate (misuse of the toothbrush and floss)
Gum Disease
The consumption of certain foods such as garlic or onion
Consumption of tobacco and alcohol
A dry mouth caused by certain drugs, medical disorders and a reduced saliva flow during sleep. General diseases such as cancer, diabetes, liver or kidney.