Medical Author: Melissa Conrad Stöppler, MD
Bad breath, medically known as halitosis, is a common problem. Bad breath is usually simple and preventable. Dietary factors as well as tobacco and alcohol use may all be factors in causing bad breath. Poor oral hygiene, gum disease, tooth decay, or mouth infections can also be causes of halitosis. Infections in the lungs, sinuses, or airways can also cause bad breath due to the presence of nasal secretions that may drain into the mouth. Chronic postnasal drip, for example as occurs with sinus infections, can be a cause of bad breath. Coughing up sputum from lung infections can also cause bad breath. Dry mouth (xerostomia) can be a side effect of certain medications, increasing the tendency to develop bad breath. Certain chronic diseases that severely restrict liver or kidney function may also alter the odor of the breath. Other chronic conditions that can be associated with bad breath include diabetes and acid reflux disease.
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.
Causes of Bad Breath
H. pylori (Helicobacter Pylori ) Infection
Helicobacter pylori (H. pylori) is a bacteria that causes chronic inflammation (gastritis) of the inner lining of the stomach,...
An abscessed tooth is an infection within a tooth that has spread to the root. Symptoms of an abscessed tooth may include pain,...
Alcoholism is a disease that includes alcohol craving and continued drinking despite repeated alcohol-related problems, such as...
Bronchitis is inflammation of the airways in the lung. Acute bronchitis is is short in duration (10 to 20 days) in comparison...
Chewing Tobacco (Smokeless Tobacco, Snuff)
Chewing tobacco (snuff or smokeless tobacco) has more nicotine absorbed into the system than by smoking a cigarette. Chewing...
Diabetes (Type 1 and Type 2)
Diabetes is a chronic condition characterized by high levels of sugar (glucose) in the blood. The two types of diabetes are...
Dry Mouth (Xerostomia)
Dry mouth is a common side effect of many prescription and non-prescription drugs and certain medical conditions. Symptoms of dry...
A dry socket is a potential complication that can occur when a blood clot in the gums becomes dislodged after a tooth extraction....
GERD (Acid Reflux, Heartburn)
GERD (gastroesophageal reflux disease) is a condition in which the acidified liquid contents of the stomach backs up into the...
Gum disease is caused by plaque and may result in tooth loss without proper treatment. Symptoms and signs of gum disease...
Is Gingivitis Contagious?
Gingivitis is inflammation of the gums. Poor dental hygiene, stress, smoking, some medications, and a poor diet can cause...
Kidney Failure (Symptoms, Signs, Stages, Causes, and Treatment)
Kidney failure can occur from an acute event or a chronic condition or disease. Prerenal kidney failure is caused by blood loss,...
The term oral cancer includes cancer of the mouth (oral cavity) and the back of the mouth (oropharynx). Red and white patches...
Pericoronitis is inflammation of the gum tissue around the molars. Pericoronitis commonly occurs in teens or young people when...
Pneumonia is inflammation of the lungs caused by fungi, bacteria, or viruses. Symptoms and signs include cough, fever, shortness...
Sinus Infection (Sinusitis)
Sinus infection (sinusitis) is caused by allergies, infection, and chemicals or other irritants of sinuses. Signs and symptoms...
Smoking (How to Quit Smoking)
Smoking is an addiction. More than 430,000 deaths occur each year in the U.S. from smoking related illnesses. Secondhand smoke or...
Strep throat is a bacterial infection of the throat. Signs and symptoms of strep throat include headache, nausea,...
Thrush (Oral Candidiasis)
Thrush is an infection of the mouth caused by the Candida fungus. Symptoms of Thrush include pain or difficulty swallowing, a...
Tonsillitis is a contagious infection with symptoms such as: Bad...
Upper Respiratory Tract Infection
An upper respiratory infection is a contagious infection of the structures of the upper respiratory tract, which includes the...
Other Causes of Bad Breath
Examples of Medications for Bad Breath
WebMD Oral Health
Get tips for a healthy mouth.