Yet persistent halitosis can lead to significant social embarrassment.
More than £2 million each year is spent on mouth cleansers and breath fresheners in the UK alone.
What makes breath smell?
Breath only smells when certain aromatic chemicals dissolve within it.
Unfortunately many of these chemicals are regularly produced when proteins from food are broken down by bacteria in the mouth.
- methyl mercaptan (colourless gas found in foods like nuts and cheese, smells like rotten cabbage)
- putrescine (gas produced when the body breaks down amino acids in food, smells of decaying meat)
- Hydrogen sulphide (gas produced by bacteria in the colon and when the body breaks down amino acids in food, smells like rotten eggs).
These chemicals can be absorbed into your bloodstream from the bowel and then circulated around the body until they are excreted via the lungs in breath.
In this way, garlic rubbed into the soles of your feet can later be detected in trace amounts in your breath.
Practically everyone has a degree of halitosis first thing in the morning.
When we sleep, saliva flow drastically reduces while your tongue and cheeks move very little. This allows:
- food residues to stagnate in the mouth
- Dead cells to accumulate that would normally be shed from the surface of your tongue, gums and the inside of the cheeks.
As bacteria in your mouth start to work on and breakdown these residues, they generate an unpleasant smell.
Although normal, anyone with nasal congestion who mouth-breathes at night is more likely to be affected.
Morning breath usually disappears after breakfast and daily brushing, because saliva starts to flow again and any leftover residues are washed away and swallowed.
Occasional bad breath
The most common causes of occasional halitosis include smoking cigarettes or cigars, drinking alcohol or eating certain foods.
Culprits that are often to blame include onions, garlic, curries, cured foods like salami and cooked foods like kippers.
Smoking also reduces the flow of saliva in its own right and so worsens bad breath.
Crash dieting or fasting can also lead to halitosis. When the body no longer has a supply of carbohydrates, it first breaks down glucose stored in the muscles and liver.
After a few hours, the body begins to break down its fat stores. The waste products of their metabolism, known as ketones, give breath a distinctive sweet and sickly smell.
You can smell this on the breath of anyone who has vigorously exercised but who hasn’t eaten enough carbohydrates before or after their workout.
People on strict high-protein diets experience the same effect for similar reasons.
What are the medical causes of bad breath?
Most reasons for halitosis are sited in the mouth.
Gum disease is the most common reason for bad breath and is caused by plaque.
Plaque is a mixture of food residues, dead gum cells and bacteria that forms between the gum and the tooth. The bacteria create an unpleasant odour and contribute to bleeding gums and loosening of teeth.
The cause of gum disease is often bad oral hygiene. If you do not regularly brush your teeth you will experience bad breath.
A coated, furry tongue is often a sign of indigestion, smoking or dehydration – all of which can make breathe smell.
Any infections around the mouth and throat might be significant. Nasal congestion, sinus infections, tonsillitis and swollen adenoids could all contribute. So could indigestion caused by acid reflux from a hiatus hernia.
Even lung disorders such as chronic bronchitis and bronchiectasis (where infected sputum is present) may play a part.
Consider too, any medications you might be taking. Anything that dries up saliva as a side-effect, such as amitriptyline (an antidepressant), may add to the problem.
How do you know if you have bad breath?
Here are some useful pointers, so you don’t have to rely on others telling you.
- Lick the inner surface of your wrist. Wait a few seconds and sniff the licked area. Is there an odour?
- Do you smoke at times other than mealtimes when the odour is diluted by food, drink and saliva?
- Do your gums look swollen or puffy and do they bleed when you brush them?
- Does your dentist or hygienist comment on your gum disease (gingivitis) and suggest more efficient brushing and flossing?
Start with the dentist and hygienist, because the root of the problem is usually dental.
Proper brushing techniques and regular flossing can work wonders. Brushing a furry tongue with a tongue cleaner is helpful.
- Avoid smoking, alcohol and spicy foods.
- Clean your mouth after eating milk products, fish and meat.
- Chewing sugar-free gum helps because it encourages the flow of saliva without contributing to tooth decay.
- Use a mouthwash to get rid of bacteria and bits of food that you may have missed when brushing.
- Deodorising mouth sprays can mask halitosis in the short term, but you need antibacterial and antiseptic preparations with a longer duration of action to make any lasting difference. Your dentist can advise you on what will be most appropriate.
When mouth infections are implicated as a cause of bad breathe, treatment with an antibiotic such as metronidazole can be effective in getting rid of bacteria that do not need oxygen to survive (anaerobic bacteria) and thereby improving symptoms.
When indigestion or acid reflux are implicated as a cause of bad breathe, treatment to eradicate a type of bacteria called Helicobacter pylori (H. pylori for short) may be effective in improving symptoms.
Before you have the antibiotics, you should be tested to see whether you have the bacteria.
There are several ways of testing for H. pylori. It could be a breath test or it could be a test that’s done on a blood sample or a stool sample – your GP will be able to explain what is involved.