Bad breath is a common problem that can affect anyone at any age.
About one in four people are thought to have bad breath (halitosis) on a regular basis.
What causes bad breath?
Bad breath can be the result of numerous things, but it's usually caused by poor oral hygiene. If bacteria builds up in your mouth, it can cause your breath to smell.
Bacteria break down pieces of food in the mouth, releasing unpleasant-smelling gas. Any food trapped in your teeth will be broken down by bacteria, causing bad breath.
Persistent bad breath can sometimes be a sign of gum disease.
Eating strongly flavoured foods, such as onions and garlic, can also cause your breath to smell, as can smoking and drinking a lot of alcohol.
Occasionally, bad breath can occur following an infection or illness, or as a result of taking certain types of medication.
Treating and preventing bad breath
Improving oral hygiene is usually enough to cure bad breath and prevent it happening again.
Your dentist can advise you about ways to improve your oral health and will recommend:
regularly brushing your teeth and gums
flossing between your teeth
keeping your tongue clean
When to see your GP
If you still have bad breath after making changes to your dental hygiene, see your GP. There may be a medical cause that needs investigating.
Don't try to hide the smell of your breath before visiting your dentist or GP, because it will make it more difficult for them to find out what's causing the problem.
Do I have bad breath?
It's not always easy to tell if you have bad breath. Other people may notice it first, but could feel uncomfortable telling you.
A simple test to find out whether you have bad breath is to lick the inside of your wrist with the back of your tongue and wait for a few seconds until the saliva dries. If your wrist smells unpleasant, it's likely your breath does too.
Learn about the causes of bad breath, how to prevent it and what to do if you already have it. Part of a series on embarrassing conditions.
Causes of bad breath
Bad breath (halitosis) has a number of possible causes.
Poor oral hygiene
The most common cause of bad breath is poor oral hygiene.
Bacteria that build up on a person's teeth, tongue and gums can cause plaque (the soft, white deposit that forms on the teeth's surface), gum disease and tooth decay.
The bacteria combine with saliva to break down food particles and proteins – this releases an unpleasant-smelling gas.
If you don't brush and floss your teeth regularly, any food trapped between your teeth will be broken down by the bacteria, causing bad breath.
Bacteria can also live in the rough surface of your tongue. Therefore, as well as brushing your teeth, cleaning your tongue can also help control bad breath.
Having regular dental check-ups will ensure that any oral hygiene problems are picked up and treated early. Your dentist can advise on how often you need a check-up.
Food and drink
Eating strongly flavoured foods – such as garlic, onions and spices – is likely to make your breath smell. Strong-smelling drinks – such as coffee and alcohol – can also cause bad breath.
Bad breath caused by food and drink is usually temporary, and can be avoided by not eating or drinking these types of food and drink too often. Good dental hygiene will also help.
Smoking is another cause of bad breath. As well as making your breath smell, smoking can also stain your teeth, irritate your gums and lessen your sense of taste.
Smoking also increases your risk of developing gum disease, which is another cause of bad breath. Stopping smoking will lower your risk of gum disease and thus help prevent bad breath.
Crash dieting, fasting and low-carbohydrate diets can also cause bad breath. These cause the body to break down fat, which produces chemicals called ketones that can be smelt.
Some types of medication can also cause bad breath. Medications associated with bad breath include:
nitrates – which are sometimes used to treat angina (chest pain caused by a restriction in the blood supply to the heart)
some chemotherapy medication
If the medication you're taking is causing bad breath, your GP may be able to recommend an alternative.
In rare cases, bad breath can be caused by certain medical conditions.
Dry mouth, also known as xerostomia, affects the flow of saliva. A lack of saliva can cause bacteria to build up in the mouth, leading to bad breath.
Dry mouth can sometimes be caused by salivary gland problems or breathing through your mouth instead of your nose.
In some cases, gastrointestinal conditions may cause bad breath. For example, H. pylori infections (bacterial infections of the stomach lining and small intestine) and gastro-oesophageal reflux disease (GORD) have been linked with bad breath.
If a gastrointestinal condition is thought to be causing your bad breath, you may need to have an endoscopy. This is a procedure where a piece of equipment called an endoscope is used to examine an area inside the body, such as your airways or abdomen.
Other medical conditions that can cause bad breath include:
lung, throat or nose infections, such as bronchiectasis
Some people are convinced they have bad breath when they don't. This psychological condition is called halitophobia.
People with halitophobia are paranoid about the smell of their breath. They often misinterpret other people's behaviour and comments, thinking they're suggesting they have bad breath. They become fixated with cleaning their teeth, chewing gum and using mouth fresheners.
Treatment for halitophobia involves talking therapies and cognitive behavioural therapy (CBT), to help the person overcome their paranoia and fixation on the smell of their breath.
Treating and preventing bad breath
Treatment for bad breath (halitosis) will depend on its cause.
Usually, the most effective treatment is improving your dental hygiene. As part of your daily routine, you should:
Brush your teeth and gums.
Floss between your teeth.
Clean your tongue.
Cleaning your teeth
Your dentist will probably recommend that you brush your teeth at least twice a day using fluoride toothpaste.
Here are some tips on how to brush your teeth and keep your mouth healthy:
Choose a small or medium-sized toothbrush with soft, multi-tufted synthetic bristles.
Replace your toothbrush every three to four months.
Brush your teeth for at least two minutes. Keep a toothbrush at work or school so you can brush your teeth after lunch.
Brush all areas of your teeth, paying particular attention to where your teeth and gums meet.
Your dentist or oral hygienist may recommend using a special single-tufted brush for specific problem areas of your mouth.
Use a separate toothbrush or a tongue scraper to lightly brush your tongue. Some toothbrushes have a tongue cleaner on the back of the brush head.
Use dental floss to clean between your teeth and remove trapped food that could cause tooth decay. Brushing on its own only cleans about 60% of the tooth’s surface.
Your dentist may recommend that you rinse your mouth daily using an anti-bacterial or anti-odour mouthwash. This shouldn't replace brushing, but can be included as part of your daily routine.
To help prevent tooth erosion, avoid brushing your teeth for 30 minutes after drinking an acidic drink, such as fruit juice, or eating acidic fruit, such as oranges.
If you wear dentures, you should take them out at night to give your mouth a chance to rest. Clean your dentures thoroughly before putting them in the next morning. Follow the advice outlined below.
Don't use toothpaste to clean your dentures, as it can scratch the surface and cause stains.
Clean your dentures thoroughly using soap and lukewarm water, denture cream or a denture-cleaning tablet.
Use a separate toothbrush to clean your dentures.
If you follow this routine, your dentures should stay clean and fresh. It will also help prevent the build-up of plaque, which can cause bad breath
Fresh breath tips
Eat a healthy, balanced diet and avoid eating strongly flavoured or spicy food.
Cut down on sugary food and drink, as it can increase the amount of bacteria in your mouth.
Reduce your alcohol consumption.
Cut down on coffee.
Drink plenty of water to help prevent your mouth becoming dry.
Chew sugar-free gum after eating, to stimulate the flow of saliva. This will help clean away any remaining food particles.
Make sure you visit your dentist for regular check-ups. Having regular dental check-ups will ensure that any plaque is removed from your teeth, particularly in areas that are difficult to reach.
Your dentist can recommend the best way to clean your teeth and gums, and point out areas you might be missing. They can also identify any signs of gum disease and ensure early treatment.
If your bad breath is caused by a gastrointestinal problem, such as an H. pylori infection or gastro-oesophageal reflux disease (GORD), you may be referred to a gastroenterologist.
Your recommended treatment will depend on the specific gastrointestinal condition that you have. For example, if you have a stomach ulcer, you may need a combination of two or three different antibiotics and a proton pump inhibitor (PPI). This is known as eradicaton therapy.