Bad breath: Causes and tips for controlling it

Good oral hygiene is the best weapon to fend off bad breath

Halitosis refers to the condition of unpleasant mouth odour, and most people have this condition from time to time. However, our shared experience doesn't make it any less embarrassing.

Knowing what causes bad breath can help you reduce the risk:

Bad breath triggers:

  • Poor oral hygiene

  • Dry mouth

  • Infections in the mouth

  • Diet

  • Health conditions

Poor Oral Hygiene allows food particles to collect on the surface of the tongue, between the teeth and along the gum tissue that surrounds the teeth. Naturally occurring bacteria in your mouth then break down those food particles, releasing chemicals that have a strong odour.

People with a dry mouth are at an increased risk of experiencing bad breath as saliva helps wash food particles from your mouth. Some medications, mouth breathing and smoking can contribute to dry mouth.

Infections in the mouth, such as tooth Decay (dental caries), gum disease or mouth sores related to other conditions and surgical wounds may contribute to bad breath.

The bacterial film called plaque that occurs naturally in your mouth can build up if not removed regularly through good oral hygiene practices. The bacteria in plaque give off an odour that affects your breath.

Foods like garlic and onions, in particular, can make your breath smell. Diets high in protein and sugar also have been associated with bad breath. Once your food is digested, chemicals that cause odour can be absorbed into your bloodstream and from there into your lungs; these chemicals are then exhaled.

Certain medical conditions are also associated with mouth odour such as infections in the nose, throat or lungs; chronic sinusitis; disturbances in your digestive system.

Prevention and Treatment of Bad Breath:

The management of halitosis involves determining and eliminating the causes which include identifying any contributory factors because certain medical conditions are also associated with mouth odour.

Having said that, more than 90% of cases of halitosis originate from the mouth, so good oral hygiene is key. Caring for your mouth will help limit food residue and plaque buildup and reduce the risk of developing caries and periodontal disease.

Bad breath dos and don'ts:


• Visit your dentist regularly for checkups and cleans.

• Brush your teeth twice a day with a fluoride-containing toothpaste and floss/clean between your teeth once a day.

• Brush your tongue, too, to remove bacteria that contribute to oral odours (especially in the back, where most of these bacteria are found). Ask your dentist to recommend a tongue cleaner.

• Drink plenty of liquids.

• Chew sugar-free gum for a minute or two at a time, especially if

your mouth feels dry.

• Clean your mouth after eating fish, meat, garlic, onion, drinking

milk products, coffee, and smoking.

• If you wear removable dentures, take them out at night and brush them thoroughly with a denture cleanser before replacing them the next morning. Unless your dentist advises otherwise, soak dentures overnight in an antiseptic solution.

• Get control over the problem. Ask a family member to tell you

whenever you have bad breath, and talk to your dentist about your concerns.

Do not:

• Let your concern about having bad breath ruin your life. We are here to help!

• Drink too much coffee - it may make the situation worse

• Clean your tongue so hard that it hurts

• Rely on mouthwash alone - practise complete oral hygiene


Lee PPC, Mak WY, Newsome P. The aetiology and treatment of oral halitosis: an update. Hong Kong Med J 2004;10(6):414-418.

American Dental Association (ADA)

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