Bad or Changed Breath - Topic Overview
When is bad breath most likely to occur?
has bad breath from time to time, especially first thing in the morning. You
also may have bad breath when you are hungry, when you are dieting, or after
eating foods with a strong odor, such as garlic, onions, or pastrami.
What causes bad breath?
Many things can cause bad
breath. A major cause is decreased
saliva. Saliva has a cleaning action that helps reduce
or eliminate bad breath. When saliva decreases, bacteria can grow, causing bad
Bad breath caused by a decrease in saliva may be
- In the morning. The flow of saliva almost
stops during sleep. The reduced cleaning action of the saliva allows bacteria
to grow, causing bad breath.
- When you are hungry. Bad breath is
more common in people who miss meals or are dieting. Chewing food increases
saliva in the mouth. When you are not eating, saliva decreases and bacteria
growth increases, causing bad breath.
- When you are
dehydrated. When you become dehydrated, you do not
produce as much saliva. The reduced cleaning action of the saliva allows
bacteria to grow, causing bad breath.
- From diseases that affect the
salivary glands, such as
Sjögren's syndrome or
- When you are taking certain
- After drinking alcohol beverages.
Other causes of bad or changed breath include:
- Eating foods with a strong odor, such as
garlic, onions, or pastrami.
- Smoking or using smokeless (spit)
tobacco, such as snuff or chewing tobacco.
- Bacteria and
plaque buildup in the mouth from food caught between
teeth, dentures, or dental appliances.
Mouth and throat problems that can cause mouth odor
- Throat or mouth infections, such as
- Dental problems, such as
- Gum disease (periodontal disease), which may cause a metallic breath odor.
- Tonsils with deep tunnels (crypts) that trap food
- Throat or mouth cancers.
Problems in other areas of the body that can cause mouth
- Problems with the nose, such as a sinus
nasal polyps, or an object in the
- Diabetes. A symptom of very high blood
sugar is a strong, fruity breath odor.
- Digestive system disorders,
such as reflux (gastroesophageal reflux disease), bowel problems, or
- Human immunodeficiency virus (HIV) infection.
- Lung problems, such as an infection or cancer.