Patient information from BMJ

Bad breath

Last published:Sep 27, 2021

Bad breath is a common problem. It can be embarrassing, but there are treatments that can help.

We've looked at the best and most up-to-date research to produce this information. You can use it to talk to your dentist or doctor and decide which treatments are right for you.

What happens?

Everyone gets bad-smelling breath sometimes. It’s common first thing in the morning and after eating strong-smelling foods, such as onions and garlic. It usually goes away when you clean your teeth.

But sometimes bad breath lasts through the day. Doctors call this halitosis. It’s often caused by dental problems, gum disease, or bacteria on your tongue.

Gum disease is caused by plaque. Plaque is a build-up of bacteria that coats the teeth, which can then infect your gums. Early, mild gum disease is called gingivitis. Advanced gum disease is called periodontitis.

Bacteria that grow on your tongue can give off bad-smelling gasses and cause bad breath. This is more likely to happen if you smoke or don't brush your teeth regularly.

Some people worry that they have bad breath when they don't. They continue to believe that they have bad breath even after they've been examined and reassured. Doctors call this pseudo-halitosis.

Other things that can sometimes cause bad breath include diseases that affect the lungs or digestive system, such as infections. So if you have bad breath that doesn't get better with the usual treatments you should see your doctor. You may need treatment for another condition.

What are the symptoms?

People may notice an unpleasant smell when you talk or breathe out. It's possible to have bad breath without knowing. That's because you get used to the smells that your own body makes. If you think that you might have bad breath you could ask a trusted friend, or visit your dentist.

You can get a rough idea of what your breath smells like by licking your wrist, waiting a minute for it to dry, then smelling your wrist. That tells you how your tongue smells.

Your dentist may be able to give you all the help you need with bad breath. As well as testing your breath, your dentist should check your teeth, gums, and tongue.

If your dentist can’t find any problems but agrees that your breath smells bad, he or she may suggest that you see your doctor. Bad breath is sometimes caused by a problem somewhere else in your body.

What treatments work?

The treatment you need depends on what is causing your bad breath.

Bad breath not caused by another condition

If you have bad breath that is not caused by gum disease or by another physical condition, you probably just need to make sure you practise good mouth hygiene.

First of all, this means making sure that you brush your teeth well, twice a day, with a fluoride toothpaste. You can also use dental floss to clean between the teeth. If you wear dentures, make sure you clean them thoroughly each day.

You could also try mouthwashes that kill bacteria. One common type contains a chemical called chlorhexidine. But there are other types.

If you still have bad breath after doing all these things you could try tongue scraping, to get rid of bacteria on the tongue that can cause bad smells. You will need to do this regularly - perhaps every few days. You do it with a toothbrush or an instrument called a tongue scraper.

Masking bad breath with things like chewing gum and breath mints might work for a short time but it won't get rid of the cause of your bad breath.

Bad breath caused by gum disease or another condition

If you have mild gum disease (gingivitis) your dentist will advise you to clean and floss your teeth thoroughly every day. He or she may also scrape the plaque from your teeth. This is called scaling. Your dentist will probably also recommend that you use a mouthwash that contains chlorhexidine.

If your gum disease is more advanced (periodontitis) you may need more complicated treatments, like scaling below the gum, root planing, or flap surgery. These remove plaque from the parts of your teeth covered by the gums. You’ll have a local anaesthetic to numb your gums first.

Bad breath can sometimes be the result of other medical problems, such as conditions that affect the mouth, throat, or nose. If your symptoms persist after you have tried better mouth hygiene, and you don't have gum disease, it's a good idea to see your doctor to rule out any other causes.

Diseases that affect the lungs and the digestive system can also cause bad breath. So, once again, if your symptoms don't get better with the usual treatments, it's a good idea to see your doctor.

What will happen to me?

Most people can cure bad breath themselves by keeping their mouths clean. But if your breath doesn't get any better, your dentist will probably be able to help.

If your dentist can't find any sign of bad breath, he or she will reassure you that your breath is perfectly acceptable.

If you're still worried about having bad breath, even after you've been reassured by your dentist, you may have a condition called pseudo-halitosis. This is a strong fear of having bad breath, even though your breath actually smells fine. If this affects you, you may need help from a psychologist or psychiatrist.