Do people tend to take a step back when you’re talking to them face-to-face? You could be among the 25 percent of people who suffer from halitosis or chronic bad breath.

“Most cases are caused by an imbalance of the 800 species of bacteria in your mouth,” says dentist Dr Geoffrey Speiser. “When this happens, the remaining bacteria, most of it coating your tongue and throat, produce the sulphur gases that cause bad breath.”

Take the bad breath test: Use a teaspoon to gently scrape your tongue at the very back, towards the gag reflex. This is where 90 percent of bad-breath bacteria live. If the spoon smells bad, so does your breath.

Here, Speiser explains the causes of and solutions to halitosis.

Dehydration

Your mouth is dry and your tongue sticky, especially in the morning. You may also notice a metallic taste.

The problem
Smoking, drinking and mouth-breathing all contribute to dehydration. This can also slow the production of the saliva you need for a healthy mouth.

Prevention
Drink when you’re thirsty and don’t skip meals. Be aware that alcohol can also dehydrate.

The fix
Chewing sugarless gum for five minutes after meals will help to stimulate your salivary glands.


Food or smoking

Take the test (above) to see if your breath is affected by what you are putting in your mouth.

The problem
Alcohol, protein and foods high in acid can affect the bacteria in your mouth and contribute to the problem.

Prevention
If you’re really worried about food breath, avoid problem ingredients, such as garlic, onions, curry and coffee. Quit smoking – you’ll instantly smell nicer and avoid a dry mouth.

The fix
Chewing on fresh parsley may mask onion breath. Regularly clean your mouth (teeth, gums and tongue) to remove the bacteria film that feed off protein in foods like dairy.


Sickness

Excess mucus at the back of the throat, and a dry mouth.

The problem
Colds and flu can cause bad breath as bacteria grow in the excess mucus. Also, some medications, such as blood pressure tablets and antibiotics, can upset the balance of mouth bacteria

Prevention
Use a hypertonic nasal spray, like Sinoclear or Fess Sinu-Cleanse, to clear congestion in your nose and throat.

The fix
If you have an infection or are taking antibiotics, a probiotic called Streptococcus salivarius K12 can help restore balance. See your doctor if you think your bad breath is caused by an underlying condition or your medication.


Poor oral hygiene

Sour taste in the mouth, and/or bleeding gums.

The problem
Bleeding gums indicate gingivitis and are a sure sign that your oral hygiene needs improvement. Plaque, tongue fur and mucus in the mouth promote smelly bacteria.

Prevention
Brushing your teeth isn’t enough. You need to floss at least once a day and also clean your gums and tongue, especially if you have bad breath.

The fix
See your dentist twice a year and change your toothbrush every three months. Mouthwashes, gels and lozenges have a probiotic effect to restore the balance of bacteria in your mouth. For details, visit www.freshbreath.com.au.


Dieting

Ketone breath is a by-product of fat breakdown that produces a fruity, alcohol-like smell.

The problem
If you’re on an extreme diet that is high in protein and low in carbohydrates, you could have bad breath.

Prevention
The bad smell is coming from your digestive system, so the only way to prevent it is to switch diets

The fix
Unbalanced diets can throw the organisms in your mouth out of whack. Choose a less restrictive menu with a wider variety of foods.