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what causes bad breath

What Causes Bad Breath: From Diagnosis to Treatment

Reviewed by Dr. Izbel Aksit.

If there’s one thing that absolutely no one likes, that’s bad breath and tolerating bad breath is simply not an option. People can have bad breath due to several reasons. If it isn’t the oniony or garlicky breath that will subside after a few hours (or days if you really feasted on these ingredients), it is a cause for alarm. Bad breath might indicate an underlying medical condition or oral health issue. In order to understand that, you need to find out what causes bad breath. 

There’s no singular reason for bad breath. No matter what, constant bad breath makes it difficult for anyone to have a normal life. When conversing with a friend, colleague, or family member, you have to maintain a certain distance. Of course, no one wants to be known for their bad breath, and trying to keep a certain distance from everyone can have a huge impact on your social, love, and even business life. 

Feeling their own bad breath makes many people end up wondering what causes bad breath and how it can be solved? Before we jump into that, you should know a little about something called the “bad breath paradox.”

The Bad Breath Paradox

According to one study, 25% of the population has halitosis or bad breath. In 85% of the cases, the problem lies in the oral cavity. Only people with halitosis sometimes really don’t know that their breath smells bad. You might think that the other person is choosing to ignore this issue and continue with their life, but that’s not always the case. 

One study that appeared in the Journal of the American Dental Association in 1996 that the way the participants of the study rated their breath was according to their preconceived notions. That meant that even if the participants knew how to detect bad breath, their idea of how a bad breath is skewed their ability to judge how their own breath should smell. 

There’s also such a thing as “halitophobia,” where a person has an extreme fear of bad breath even when they don’t have a bad breath. It is possible for someone to develop halitophobia after they had halitosis. The fear persists even after the bad breath is treated. People can also develop halitophobia after someone points out their bad breath to them. Since it’s not a dental condition, the treatment for halitophobia can involve therapy. 

How To Find Out If You Have Halitosis? 

People with halitosis might not even know that they have bad breath, so how exactly do they find out if they have this problem? There are a few things that you can do about this. You can ask a friend or family member to smell your breath. Understandably, you might not feel comfortable with this. However, there are other ways to go about it. So, you don’t have to worry about getting a proper diagnosis. 

You can lick your wrist and smell it after the saliva dries. If it smells, there might be a problem. You can also try using a tongue scraper. After scrapping, take it out, and smell it to find out if you have bad breath. 

You can also simply go to the dentist and find out if you have bad breath. They might use a Halimeter to quantify the degree of bad breath that you have. The device measures parts-per-billion (ppb) of the compounds that are responsible for producing bad breath. According to a study published in the Journal of Neurogastroenterology and Motility (JNM), bacteria at the back of the tongue are responsible for bad breath. They produce volatile sulfur compounds (VSCs). If the Halimeter’s measurement is above 100 ppb, it indicates bad breath. 

There are other tests available to diagnose halitosis. Gas chromatography also measures VSCs to determine if a person has halitosis. Some tests find out the level of certain enzymes in the mouth that are associated with bad mouth odor or halitosis. 

What Are the Causes of Bad Breath? 

Onion or garlic may not always be responsible for your bad breath. There are more than a few reasons why you may have bad breath. 

Poor Oral Health 

Brush twice and floss once a day. It’ll make sure that the food particles that are stuck between your teeth get out. If the food remains stuck, it can lead to the build-up of plaque. It can also cause cavities and gum disease, which can itself become a cause of bad breath. When cleaning your mouth, don’t forget the tongue. The uneven surface of the tongue can also trap food particles. `

Drinking & Eating Foods That Cause Bad Breath 

By eating a lot of citrus foods, you might not be doing a favor to your mouth. The bacteria that are responsible for producing bad odor thrive in acidic environments. Surprisingly, a high-protein diet can also give you bad breath. The breakdown of protein produces ammonia, and that comes out of the body through the mouth (it may smell like cat pee). The amino acids in the cheese, together with the oral bacteria, produce sulfur compounds. Drinking coffee can make the mouth dry. Less saliva led to an increase in the number of bacteria that produce a foul smell. Drinking alcohol has the same effect. It can cause a decrease in the production of saliva. A dry mouth means more odor-causing bacteria. 

Eating foods high in sugar is probably not a great idea either. Now, the sweets may smell and taste nice to you, but the bacteria in your mouth will consume those sweets and produce bad smells. Eating healthy and balanced is a great option for anyone who wants to prevent bad odor.


If you smoke cigarettes or any other tobacco product, it is definitely going to make your mouth smell. There’s no wondering what causes bad breath here. The chemicals in the smoke will linger in your mouth and lungs, which will make your mouth smell even when you’re not smoking. The smell gets trapped in the lungs. And mouthwashes won’t help it. Hence the smoker’s breath. However, that’s not the only way your mouth suffers. Smoking can cause countless other oral health issues such as tooth decay, gum diseases, and oral cancer. 

Dry Mouth 

A condition known as xerostomia can cause a decrease in the production of saliva. It is not a disease and can happen due to different reasons. Some medicines can make the mouth go dry. It can also happen due to ageing or due to radiation therapy to the head and neck. The latter can affect the salivary glands. 

Dentures and Braces 

With braces, food particles can easily get stuck between the teeth and even in the hardware of the braces. The food is broken by the bacteria then causes bad breath. Improper cleaning of the dentures can make them smell. It can also cause infections in the mouth which can also make your mouth smell. 

Morning Breath 

Well, there’s not much you can do about that. When you’re sleeping, your mouth gets dry, and the bacteria again thrive in such environments. 

What Are the Different Treatments for Bad Breath? 

Now that you know the answer to what causes bad breath, let’s take a look at some of the treatments that are available for it. If the cause of the bad breath is plaque buildup, a dental cleaning can help. However, if the bad odor is a result of gum disease, you might need gum treatment. The problem might not always be with oral health. Chronic bad breath that doesn’t go away with proper oral hygiene might indicate an underlying health condition. Get in touch with a doctor to get yourself checked. Kidney disease or sinus infection can also give you bad breath. In this case, the bad breath will linger until the underlying health condition gets treated. 

How Can You Prevent Bad Breath? 

Brushing alone is not enough. The bristles cannot reach the area between your teeth, which is why flossing is important. Also, include an antimicrobial mouthwash in your routine. The bacteria in the spaces between the teeth can also produce a bad smell. Quit smoking to get rid of your smoker’s breath. Drink water and stay hydrated so that your mouth doesn’t get too dry. And get a dental cleaning twice a year after every 6 months. 

Summing Up the Discussion 

Bad breath is something that many people struggle with, even if for a short while. You also know the answer to what causes bad breath. Taking some medicines can dry out the mouth. Morning breath is inescapable. And so is garlic or onions. But even after maintaining proper oral hygiene, the bad smell lingers, you should get in touch with a dental professional. You might need a dental cleaning, or it could be some other health problem. You can book your appointment right away to discuss your dental treatment options. Longevita will make sure to guide you about everything.

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