Breath odor is the scent of the air you breathe out of your mouth. Unpleasant breath odor is commonly called bad breath.
Bad breath is usually related to poor dental hygiene. Not brushing and flossing regularly causes sulfur compounds to be released by bacteria in the mouth.
Some disorders will produce distinct breath odors. Some examples are:
- A fruity odor to the breath is a sign of ketoacidosis, which may occur in diabetes. It is a potentially life-threatening condition.
- Breath that smells like feces can occur with prolonged vomiting, especially when there is a bowel obstruction. It may also occur temporarily if a person has a tube placed through the nose or mouth to drain their stomach.
- The breath may have an ammonia-like odor (also described as urine-like or "fishy") in people with chronic kidney failure.
Bad breath may be caused by:
- Abscessed tooth
- Eating certain foods, such as cabbage, garlic, or raw onions
- Coffee and poorly pH-balanced diet
- Object stuck in the nose (usually happens in kids); often a white, yellow, or bloody discharge from one nostril
- Gastroesophageal reflux disease (GERD)
- Gum disease (gingivitis, gingivostomatitis)
- Impacted tooth
- Lung infection
- Poor dental hygiene
- Sinus infection
- Throat infection
- Tobacco smoking
- Vitamin supplements (especially in large doses)
- Some medicines, including insulin shots, triamterene, and paraldehyde
Some diseases that may be cause breath odor are:
- Acute necrotizing ulcerative gingivitis
- Acute necrotizing ulcerative mucositis
- Acute renal failure
- Bowel obstruction
- Chronic kidney failure
- Esophageal cancer
- Gastric carcinoma
- Gastrojejunocolic fistula
- Hepatic encephalopathy
- Diabetic ketoacidosis
- Lung abscess
- Ozena, or atrophic rhinitis
- Periodontal disease
- Zenker diverticulum
Use proper dental hygiene, especially flossing. Remember that mouthwashes are not effective in treating the underlying problem.
Fresh parsley or a strong mint is often an effective way to fight temporary bad breath. Avoid smoking.
Otherwise, follow your health care provider's instructions to treat any underlying cause of bad breath.
When to Contact a Medical Professional
Contact your provider if:
- Breath odor does not go away and there is not an obvious cause (such as smoking or eating foods that cause the odor).
- You have breath odor and signs of a respiratory infection, such as fever, cough, or face pain with discharge from your nose.
What to Expect at Your Office Visit
Your provider will take a medical history and perform a physical exam.
You may be asked the following medical history questions:
- Is there a specific odor (such as fish, ammonia, fruit, feces, or alcohol)?
- Have you recently eaten a spicy meal, garlic, cabbage, or other "odorous" food?
- Do you take vitamin supplements?
- Do you smoke?
- What home care and oral hygiene measures have you tried? How effective are they?
- Have you had a recent sore throat, sinus infection, tooth abscess, or other illness?
- What other symptoms do you have?
The physical exam will include a thorough inspection of your mouth and nose. A throat culture may be taken if you have a sore throat or mouth sores.
In rare cases, tests that may be performed include:
- Blood tests to screen for diabetes or kidney failure
- Endoscopy (EGD)
- X-ray of the abdomen
- X-ray of the chest
Antibiotics may be prescribed for some conditions. For an object in the nose, your provider will use an instrument to remove it.
Bad breath; Halitosis
Murr AH. Approach to the patient with nose, sinus, and ear disorders. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 426.
Stein PS, Miller CS, Fowler CB. Oral disorders. In: Ham RJ, Sloane PD, Warshaw GA, Potter JF, Flaherty E, eds. Primary Care Geriatrics: A Case-Based Approach. 6th ed. Philadelphia, PA: Elsevier Saunders; 2013:chap 53.
Review Date 2/22/2016
Updated by: Michael Kapner, DDS, general and aesthetic dentistry, Norwalk Medical Center, Norwalk, CT. Review provided by VeriMed Healthcare Network.Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.