These particles may rot and cause foul odors. In addition, food particles over time can promote the growth of bacteria, which can also cause foul odors. The bacteria can also lead to tooth decay
and gum disease
Foods with strong odors also affect the air a person exhales. Foods commonly known to contribute to bad breath include onions and garlic, exotic spices (such as curry), some cheeses, fish, and acidic beverages such as coffee. Foods are absorbed into the bloodstream and then transferred to the lungs, causing noticeable odors when exhaled. These foods may also cause gastrointestinal upset and belching, which can contribute to bad breath. In addition, certain supplements
such as fish oil
capsules can contribute to bad breath.
Low carbohydrate diets
may also cause what is known as 'ketone breath.' so-called 'low carb' diets cause the body to burn fat as its energy source. The end-product of making this energy are ketones, which cause a fruity acetone-like odor on the breath when exhaled.
bad breath can also be caused by decreased flow of saliva, which is a vital part of the digestive process and removes odor-causing particles in the mouth. Also called xerostomia, dry mouth may be caused by medications, breathing through the mouth, or salivary gland
Tobacco products - in addition to causing bad breath, smoking
or chewing tobacco-based products can stain teeth, irritate gum tissue, and exacerbate tooth decay.
Certain medical disorders may cause bad breath, for example:
gum or periodontal infection, throat infection (pharyngitis
), local infection in the respiratory tract, chronic sinusitis
and/or post-nasal drip, chronic bronchitis
, diabetes, acid relux, certain liver or kidney disease, sjogren's syndrome (causes xerostomia), and lactose intolerance
Dentures or dental appliances, such as braces, can contribute to bad breath. Most often it is due to food particles that are not properly cleansed from the appliances. Loose-fitting dentures can contribute to sores and localized infections in the mouth, which can cause bad breath.
Finally, morning breath is the appearance of bad breath in the morning that results from an
overnight accumulation of bacteria in the mouth. Some people breathe through their mouth at night, which can cause dry mouth and worsen morning breath.