Bad breath facts for kids

"Halitosis" redirects here. For the genus of molluscs, see Haliotis.

Quick facts for kids Bad breath
Synonyms	Halitosis, fetor oris, oral malodour, putrid breath

Symptoms	Unpleasant smell present on breath
Complications	Anxiety, depression, obsessive compulsive disorder
Types	Genuine, non-genuine
Causes	Usually from inside the mouth
Treatment	Depends on cause, tongue cleaning, mouthwash, flossing
Medication	Mouthwash containing chlorhexidine or cetylpyridinium chloride
Frequency	~30% of people

Bad breath, also known as halitosis, is when your breath has a noticeably unpleasant smell. It can make people feel worried or anxious. Sometimes, it's also linked to feeling down or having very strong, repeated thoughts.

There are two main types of bad breath: genuine and non-genuine. When someone truly has bad breath, about 85% of the time, the smell comes from inside their mouth. The other cases might be due to problems in the nose, sinuses, throat, lungs, or stomach. Very rarely, bad breath can be a sign of a serious medical condition like liver problems. Non-genuine cases are when someone thinks they have bad breath, but others can't actually smell it. This happens in a large number of cases.

How you treat bad breath depends on what's causing it. Simple steps often include cleaning your tongue, using mouthwash, and flossing your teeth. Some mouthwashes with special ingredients like chlorhexidine or cetylpyridinium chloride might help. Cleaning your tongue might also be useful. Treating other health issues like gum disease or tooth decay can also make a difference. If someone wrongly believes they have bad breath, talking to a counselor can be helpful.

About 6% to 50% of people experience bad breath. It's the third most common reason people visit the dentist, after tooth decay and gum disease. It tends to become more common as people get older. Bad breath is often seen as something embarrassing, and people who have it might feel judged. In the United States, people spend over $1 billion each year on mouthwash to try and fix it.

What are the signs of bad breath?

Bad breath is simply when your breath has a noticeable, unpleasant smell. This can make people feel anxious or worried. It's also sometimes connected to feelings of sadness or even symptoms of obsessive-compulsive disorder.

What causes bad breath?

Causes from inside your mouth

In about 90% of real bad breath cases, the smell starts right in the mouth. This is called oral halitosis.

The most common causes are tiny films of bacteria (called biofilm) on the back of your tongue or other parts of your mouth, usually because of poor oral hygiene. These bacteria break down proteins into smelly gases. These gases often contain sulfur, which smells like rotten eggs. Other parts of the mouth can also cause bad breath, but less often. These include spaces between teeth, faulty dental work, food stuck between teeth, infections, and unclean dentures. Mouth sores from viruses can also contribute.

The strength of bad breath can change throughout the day. Eating certain foods like garlic or onions, or smoking, can make it worse. Since your mouth is less active and has less oxygen at night, your breath is usually worst when you wake up (this is called "morning breath"). Bad breath can be temporary, often going away after eating, drinking, brushing, flossing, or using mouthwash. But some people have persistent (chronic) bad breath, which affects about 25% of people to different degrees.

Your tongue

The tongue is the most common place for bad breath to start inside the mouth. Bacteria on the tongue produce smelly compounds. This accounts for 80% to 90% of all mouth-related bad breath cases. Many bacteria live naturally on the back of your tongue, where they aren't easily disturbed. This part of the tongue can be dry and hard to clean. Its bumpy surface is a perfect home for bacteria that thrive without much oxygen. These bacteria feed on food bits, dead skin cells, and mucus from your nose. When left on the tongue, these bacteria can create smells like rotten eggs (from sulfur compounds) or other unpleasant odors. A visible white coating on the tongue is often a sign of bad breath, though not always. People with gum disease often have more tongue coating.

Your gums

Small grooves exist between your teeth and gums. These can become inflamed if you have gingivitis (early gum disease). More advanced gum disease, called periodontitis, can also cause severe bad breath. People with uncontrolled diabetes are more likely to have gum infections, which can lead to pus and bad breath. Cleaning under the gums can greatly improve mouth odor. The bacteria that cause gum disease are known to produce smelly sulfur compounds. The amount of these compounds in your breath is linked to how deep gum pockets are. However, not everyone with gum disease has bad breath, and not everyone with bad breath has gum disease.

Other causes in the mouth

Other less common causes of bad breath from inside the mouth include:

Deep tooth decay, where food can get stuck.
Recent tooth extraction sites, which can be good places for bacteria to grow.
Food stuck between teeth, especially if teeth are missing or crooked. This food can rot and release bad smells.
Unclean plastic dentures, which can trap bacteria and yeast.
Mouth infections or sores.
Not eating for a long time (fasting).
Feeling stressed or anxious.
Changes during the menstrual cycle in women.
Smoking, which is linked to gum disease and other mouth problems.
Volatile foods like onions, garlic, or cabbage. These can leave smelly leftovers in your mouth or cause odors through your bloodstream.
Certain medications that cause dry mouth, leading to more bacteria growth.

Causes from your nose and sinuses

Sometimes, the air coming out of your nostrils can have a strong smell that's different from your mouth odor. This can happen due to sinus infections or foreign objects stuck in the nose.

Causes from your tonsils

There's some debate about how often tonsil problems cause bad breath. Some say it's a significant cause after mouth issues. Conditions like chronic tonsillitis (where cheese-like material can form in the tonsils) or tonsil stones can be linked to bad breath.

Causes from your esophagus

The valve between your stomach and esophagus (food pipe) might not close properly, perhaps due to a hiatal hernia or acid reflux. This can allow stomach acid and gases to escape into your mouth. A pouch in the esophagus (Zenker's diverticulum) can also trap old food, leading to bad breath.

Causes from your stomach

Most experts agree that the stomach is a very rare source of bad breath. The esophagus is usually closed, so if gas or smelly substances are constantly coming up from the stomach, it usually means a more serious health problem is present, like severe reflux. For example, the smell from eating garlic doesn't come from the stomach because it's not broken down there.

Causes from body-wide diseases

A few body-wide (systemic) medical conditions can cause bad breath, but these are not common. Such conditions include:

Fetor hepaticus: a rare type of bad breath caused by severe liver failure.
Lung infections.
Kidney infections and kidney failure.
Certain types of cancer.
Trimethylaminuria ("fish odor syndrome"), where the body can't break down a certain chemical, causing a fishy smell.
Diabetes.
Other metabolic conditions that affect how your body processes chemicals.

People with these conditions usually have other, more obvious symptoms besides just bad breath.

When someone thinks they have bad breath but don't

About a quarter of people who seek help for bad breath are overly worried about it. This is called halitophobia or delusional halitosis. They are sure they have bad breath, even if others can't smell it. Bad breath concerns can seriously affect the lives of about 0.5–1.0% of adults.

How is bad breath diagnosed?

Checking your own breath

It's often hard to smell your own breath because your nose gets used to the smell. However, many people with bad breath can detect it in others. Some people think they have bad breath because of a bad taste in their mouth, but a bad taste isn't a good sign of actual bad breath.

People often find out if they have bad breath by asking a close friend.

One common home test is to lick the back of your wrist, let the saliva dry, and then smell it. However, research shows this test often makes people think their breath is worse than it is. A better way is to gently scrape the back of your tongue with a plastic spoon and smell the dried residue. There are also home tests that check for certain chemicals on your tongue, but we don't have many studies showing how well they work. Since breath odor changes throughout the day, you might need to test multiple times.

Professional testing

If bad breath is constant and other dental or medical issues have been ruled out, special testing might be needed. Many dental offices and clinics now offer to diagnose and treat bad breath. They might use laboratory methods like:

Halimeter: A device that measures sulfur gases in your mouth. It's good for detecting certain bacteria, but it has some downsides. It might not pick up all types of smelly gases, and certain foods like garlic can give false readings.
Gas chromatography: More advanced machines that can measure specific smelly gases in your breath very accurately.
BANA test: A test that looks for an enzyme in your saliva that shows certain bad-breath bacteria are present.

Even with these machines, the best way to measure bad breath is still for trained experts to actually smell and score the odor. This is called "organoleptic measurement."

How is bad breath managed?

To improve bad breath, you can try to reduce bacteria in your mouth, use products to cover the smell, or use chemicals that change the odor-causing molecules. Many different things have been tried, like special toothpastes, mouthwashes, and tongue scraping. There isn't strong evidence yet to say which methods work best. If you use tobacco products, it's recommended to stop. There's not enough evidence to show that changing your diet or chewing gum helps.

Cleaning your mouth

Brushing your teeth can help. While there's some evidence that tongue cleaning might reduce smelly molecules, we need more research to be sure. Flossing your teeth can also be useful.

Mouthwashes

Some studies suggest that antibacterial mouthrinses can help. Mouthwashes often contain ingredients like cetylpyridinium chloride, chlorhexidine, or zinc. These help kill bacteria. Some mouthwashes use essential oils. Be aware that some ingredients, like chlorhexidine, can temporarily stain your teeth.

Treating underlying problems

If you have gum disease or cavities, treating these problems is important and can improve your breath.

If doctors believe a health issue outside your mouth is causing the problem, treating that condition can also help.

For those who wrongly believe they have bad breath, talking to a counselor can be very helpful.

How common is bad breath?

It's hard for researchers to know exactly how many people have bad breath. One reason is that bad breath is often seen as embarrassing, so people might not want to talk about it or report it accurately. Also, there's no single way everyone agrees on to diagnose bad breath. Because of these challenges, the numbers reported vary widely.

History and culture of bad breath

The earliest records of bad breath go back to ancient Egypt, where detailed recipes for toothpaste were made even before the pyramids were built. An ancient Egyptian scroll from 1550 BC describes tablets to cure bad breath using ingredients like incense, cinnamon, and honey. Ancient Greek doctors suggested using red wine and spices as a mouthwash. Interestingly, alcohol-containing mouthwashes are now thought to make bad breath worse because they dry out the mouth, which helps bacteria grow.

Ancient Chinese emperors made visitors chew cloves before meeting them. In ancient Jewish texts, bad breath was considered a disability that could be a reason to end a marriage. Early Islamic teachings emphasized cleaning teeth and the tongue with a "siwak," a stick from a tree, which is like a natural toothbrush. During the Renaissance, a French doctor believed bad breath was caused by dangerous "miasma" (bad air) that harmed the lungs and heart.

In modern times, bad breath is a major social taboo. People care a lot about avoiding it, which is why consumers in the United States spend over $1 billion each year on mouthwashes, mints, and other products. Many of these products only cover up the smell for a short time. Some experts think our dislike of bad smells might be an old instinct to avoid spoiled food or harmful things. Body odors are also thought to play a role in choosing a partner, and a bad smell might signal illness. While bad breath has been mentioned for centuries, the social stigma might have grown over time, partly due to advertising. This could be why conditions like halitophobia are more common now.

Where did the word "halitosis" come from?

The word "halitosis" comes from the Latin word halitus, meaning 'breath', and the Greek ending -osis, meaning 'diseased' or 'a condition of'. Many people think the company Listerine invented the term "halitosis," but it actually existed before their product. A doctor named Joseph William Howe coined it in his 1874 book. However, it became widely known in the 1920s when Listerine launched a big advertising campaign. Their ads showed sad young men and women who couldn't find love because of "chronic halitosis." Before this, bad breath wasn't seen as such a big problem, but Listerine changed that. One writer said, "Listerine did not make mouthwash as much as it made halitosis." In just seven years, the company's sales jumped from $115,000 to over $8 million!

Alternative treatments

In traditional Ayurvedic medicine, chewing areca nut and betel leaf was believed to help with bad breath. In South Asia, it was a custom for lovers to chew this mixture because it freshened breath and had stimulating effects. However, chewing areca nut and betel leaf can cause tooth decay, stain teeth, and are known risk factors for oral cancer.

Some alternative medicine practitioners sell many products claiming to treat bad breath, including supplements and probiotics. Bad breath is sometimes linked to "candida hypersensitivity syndrome" (a type of yeast infection) and is claimed to be treatable with antifungal or alternative medications.

Research

In 1996, a group called the International Society for Breath Odor Research (ISBOR) was formed. Their goal is to encourage research into all aspects of breath odors from different scientific fields.