Cause | Common Features* | Tests |
---|---|---|
Disorders in the mouth (oral) | ||
Bacteria on the back of the tongue | Unpleasant-smelling tongue scrapings Healthy gums and teeth | A doctor’s or dentist's examination |
Periodontal disorders, such as gingivitis Gingivitis Gingivitis is a mild form of periodontal disease characterized by inflammation of the gums (gingivae). Gingivitis results most often from inadequate brushing and flossing but may result from... read more and periodontitis Periodontitis Periodontitis is a severe form of gingivitis, in which the inflammation of the gums extends to the supporting structures of the tooth. Plaque and tartar build up between the teeth and gums and... read more | Affected gums and teeth noted during the examination In people with a history of poor oral hygiene | A dentist’s examination |
Cancers of the mouth (most are identified during a doctor's or dentist's examination long before they cause bad odors) | Usually identified during the examination More common among older adults, who often have an extensive history of using alcohol and/or tobacco | Biopsy, CT, or MRI |
Disorders outside the mouth (extraoral) | ||
A foreign object (body) in the nose† | Often a pus-filled or bloody discharge from the nose Seen during the examination Usually in children | A doctor's examination Sometimes imaging |
Cancer of the nasal passages and upper throat† | Discomfort when swallowing | A doctor's examination |
Lung infections, such as a lung abscess Abscess in the Lungs A lung abscess is a pus-filled cavity in the lung surrounded by inflamed tissue and caused by an infection. A lung abscess is usually caused by bacteria that normally live in the mouth and are... read more , bronchiectasis Bronchiectasis Bronchiectasis is an irreversible widening (dilation) of portions of the breathing tubes or airways (bronchi) resulting from damage to the airway wall. The most common cause is severe or repeated... read more , or an infection caused by an inhaled foreign object Objects in the Nose Cotton, paper, pebbles, beads, seeds, nuts, insects, button batteries, and beans are just a few of the many objects that children, people with intellectual impairment, and people with mental... read more | Cough that produces blood or sputum (phlegm) Fevers | Chest x-ray Cultures of sputum |
Imagined halitosis (psychogenic halitosis) | Unpleasant smell not detected by others Often in people known to exaggerate other normal body sensations | A doctor's examination Sometimes a consultation with a psychologist |
Sinus infection† | A pus-filled discharge from the nose Face pain, headache, or both | A doctor's examination Sometimes CT |
Spitting up of undigested food (regurgitation) when lying down or bending over | Video of the upper digestive tract after barium is given by mouth (barium swallow) | |
Swallowed or inhaled substances | ||
Alcoholic beverages, garlic, onions, tobacco | Apparent based on the person's history Diagnosed after the doctor's examination rules out other causes | A doctor's examination Avoidance of the substance to see if symptoms go away |
* Features include symptoms and the results of a doctor's or dentist's examination. Features mentioned are typical but not always present. | ||
† The odor is typically more noticeable from the nose than from the mouth. | ||
CT = computed tomography; MRI = magnetic resonance imaging. |