(HealthDay News) -- Bad breath can be caused by something potent you had for lunch, but it can also signal an underlying health problem.

The U.S. National Library of Medicine lists these possible causes of bad breath that may need to be checked by your doctor:

• An abscessed tooth or cavity, or wearing dentures.
• Alcoholism or smoking.
• Taking certain medications.
• Having a foreign object lodged in the nostril (most common in children).
• An impacted tooth, gum disease or bad dental hygiene.
• Taking significant amounts of vitamins.
• A throat or lung infection, or sinusitis.