Halitosis is also referred to as oral malodor, but most of us know it quite simply as "bad breath." Even though it's a comparatively minor health problem, bad breath can be distressing and a bit of a social handicap. It is not a wonder that we spend millions each year on efforts to freshen our breath with various gums, sprays, and mouthwashes.
The most common cause of bad breath is the food you eat. Garlic, onions, some kinds of fish, and diets rich in fat and meat can all result in halitosis. When these foods are digested, volatile substances or chemicals are absorbed into your bloodstream and are carried to your lungs where they are exhaled in your breath. In one study, rubbing garlic on the feet actually caused bad breath!
The breakdown products of proteins in the body used for energy are exhaled through the lungs, and therefore missing meals, hunger, fasting, starvation, and low-calorie diets can also cause "hunger breath."
Because there is no flow of saliva during sleep, putrefaction (decomposition or rotting) of saliva and debris in the mouth can lead to bad breath in the morning.
Halitosis is also caused by:
Taking certain medications can also cause bad breath, especially those that reduce the flow of saliva and dry out the mouth (e.g., some antidepressants, antipsychotics, antihistamines, decongestants, and medications to reduce high blood pressure).
The awkward irony of halitosis is that many people aren't aware that they have it. This is because the cells in the nose that are responsible for the sense of smell actually become unresponsive to the continuous stream of bad odour. If you have bad breath, you may need to be told, or you may notice the negative reaction of other people when you're just too close!