You may not always know that you have bad breath. That's because odor-detecting cells in the nose eventually get used to the smell. Other people may notice and react by recoiling as you speak. Bad breath in most cases is a symptom of some other process going on in your body that needs to be addressed

Main symptoms of bad breath
Most bad breath originates in your mouth. The causes of bad breath are numerous. Symptoms depend on the underlying cause of bad breath. Major causes and associated symptoms include:

• Dental problems

  • an unusually high number of cavities
  • dry eyes (in Sjögren's syndrome)
  • food trapped between the teeth
  • pale or swollen gums
  • teeth covered with film
  • teeth covered with plaque

• Diseases - Symptoms of diabetes, lung disease, kidney failure or liver disease

• Dry mouth

  • burning in the mouth
  • difficulty speaking for a long time because of mouth dryness
  • difficulty swallowing dry foods
  • an unusually high number of cavities
  • dry eyes (in Sjögren's syndrome)

• External agents

  • a uniform yellow "coffee stain" on teeth
  • cigarette stains on fingers and teeth

• Infections in the mouth

  • a pocket of pus (abscess) at the base of a tooth
  • a denture whose fit changes
  • gums that bleed easily, especially after brushing or flossing
  • loose teeth
  • painful, open sores on the gums
  • painful, open sores on the tongue
  • pus between teeth
  • red or swollen gums

• Respiratory tract infections

  • a greenish or yellowish nasal discharge
  • fever
  • a mucus-producing cough
  • sore throat
  • swollen lymph nodes ("swollen glands") in the neck

When to seek help
Sometimes bad breath can be a sign that a medical condition needs attention right away. If you have diabetes, gastroesophageal reflux disease (GERD) or chronic liver or kidney disease, ask your doctor what bad breath may mean for your condition. Also, call your doctor if you have bad breath along with any of the following symptoms:

• a cough accompanied by mucus production
• discolored nasal discharge
• fever
• postnasal drip
• sore throat

Call your dentist promptly if you have bad breath that is accompanied by loose teeth or painful, swollen gums that bleed easily. Even if you have none of these symptoms, call your dentist or physician if your bad breath continues despite a good diet and proper dental hygiene. If the cause isn't dental, see your doctor to rule out a possible medical cause - you may need a physical examination and testing to pinpoint the underlying cause. To learn more about how doctors can diagnose possible underlying causes of bad breath, read the Diagnosing Bad Breath section that follows.