Bad breath is a common problem that can affect us at any stage in our lives. Read our guide to the causes & ways to help prevent it

The medical term for bad breath is halitosis and it can be something that happens to us only occasionally, or on a daily basis. It's thought that around one in four of us will suffer from regular bad breath at some point in our lives.

Common causes of bad breath

There are many causes of bad breath. If you’re not sure what’s triggering yours then here are the ones to look out for first: 

Poor oral hygiene

The most common cause of bad breath is a poor oral hygiene routine – in other words, not cleaning our teeth properly or regularly enough. When we eat, the bacteria naturally present in our mouths begin to multiply. If we don't regularly remove the bacteria by cleaning, they can give off unpleasant-smelling gases that cause bad breath. 

Particles of food left behind by poor brushing, or by not flossing, will also be broken down by the bacteria in our mouth and produce an unpleasant smell. Similarly, if you wear a denture or other oral appliance (such as a removable brace) and it’s not cleaned properly, bacteria can build up on the surface creating a smell.

If you have bad breath regularly, it can be a sign that you're developing gum disease. The gums may become red and swollen and may bleed while cleaning your teeth or when you touch them. 


As well as affecting the way your breath smells, smoking can also irritate your gums. This irritation puts you at a higher risk of developing gum disease, which can cause bad breath as an early symptom. 

Strong-smelling food or drink

If your bad breath comes on when you've eaten or drunk something with a strong smell, and you don't have it at other times, the chances are you've found the cause.

Can medical conditions cause bad breath?

Some medical conditions can cause bad breath, including:

• Nose, throat and lung infections such as bronchitis, tonsillitis or sinusitis

• Infection of your stomach lining with the ulcer-causing bacteria known as H. Pylori

• If you have a dry mouth as a symptom of a medical condition, such as diabetes or Sjogren's syndrome, you may experience bad breath

Some prescription medicines can cause bad breath as a possible side effect. These include:

• Nitrate medicines, used to treat angina

• Phenothiazines, a group of medicines used to treat various mental health problems

• Certain types of chemotherapy

How to prevent bad breath

The most important step you can take to prevent or treat regular bad breath is to have a good daily oral hygiene routine:

• Visit your dentist for regular check-ups

• Brush your teeth for at least two minutes, twice a day. Some people find it's easier to thoroughly clean their teeth with an electric toothbrush

• Use a toothpaste containing fluoride. Fluoride has been shown to help prevent the growth of the bacteria that cause bad breath

Floss your teeth at least once a day, preferably before brushing

• If you wear a denture, take it out each night (this gives your mouth a chance to rest) and clean it thoroughly. Your dentist or pharmacist can advise on a suitable cleaning method – they may recommend a specialist denture cleaning solution

• If you wear a removable brace or other appliance, make sure you clean it regularly. Your dentist or pharmacist can advise on the best way to do this

If you have gum disease, mouthwashes containing chlorhexidine or hexetidine can help. Your dentist or pharmacist can advise on which might be suitable for you.

Chewing sugar-free gum after eating can help stimulate your mouth to produce more saliva. This can help wash away any remaining food particles and can help keep your mouth feeling fresh and clean.

If you're ready to quit smoking, there's lots of support available to help you succeed. Talk to your pharmacist or GP for advice.

Finally, if your bad breath is caused by a particular food or drink, you can simply avoid having too much of that food or drink in future.

Why not try our top recommendations for help maintaining good oral hygiene?

Philips Sonicare DailyClean 3100 Electric Toothbrush

Go electric

Experience a new level of clean with the Philips Sonicare electric toothbrush, featuring an angled brush head for better access to the back teeth.

Sensodyne Sensitivity & Gum Whitening Sensitive Fluoride Toothpaste

A daily fluoride toothpaste

Brush for two minutes, twice a day with Sensodyne’s fluoride toothpaste, specially designed for people with sensitive teeth and gums. 

Humble Dental Floss

A flossing favourite

With a fresh minty flavouring, Humble dental floss slides easily in between your teeth and comes in a handy cardboard box rather than plastic. 

Boots Expert Antibacterial Mouthwash with Chlorhexidine*

A mouthwash for your routine

This mouthwash is specially formulated with chlorhexidine to help fight plaque and combat bad breath. 

*It is not recommended that this product is used for longer than one month unless advised by your dentist or hygienist

Steradent Active Plus Denture Daily Cleaner

Keep it clean

This daily denture cleaner provides a powerful in-depth clean and can be used twice daily on full or partial dentures. 

What is halitophobia?

Occasionally, we can become irrationally convinced that our breath smells, even when it doesn't. This belief can cause people to become very preoccupied with cleaning their teeth and freshening their breath, and can lead them to mistakenly believe others are criticising them for having bad breath. This is a recognised psychological condition, called halitophobia. 

If you're becoming distressed by the belief that your breath smells, even after being assured by others that it doesn't, see your GP for advice.

When to seek medical advice for bad breath

Bad breath can be a symptom of gum disease. If you're experiencing bad breath on a regular basis, see your dentist for a check-up. They can assess the health of your gums and advise on any treatment.

If you think your bad breath may be caused by a medicine you've been prescribed, talk to the doctor who prescribed it for you. They may be able to switch you to an alternative. In the meantime, it's very important that you keep taking your medicine. 

If you have bad breath alongside other more troublesome symptoms, for example:

• You're very thirsty or tired

• You've lost weight without meaning to

• You often have a gnawing or burning pain in your stomach 

• Any other symptoms that are worrying you

It may be a sign you have an illness or condition that needs investigating. Make an appointment with your GP to discuss your symptoms.

If you've been diagnosed with a long-term condition that's known to cause bad breath, ask about this at your next appointment.

Next steps

• The most common cause of bad breath is poor oral hygiene. You should visit your dentist for regular check-ups and clean your teeth at least twice a day using a fluoride toothpaste, as well as flossing at least once a day

• Bad breath can be an early sign of gum disease. If you have regular bad breath that persists even if you have good oral hygiene, see your dentist for a check-up

• If you have persistent bad breath alongside other symptoms that are worrying you, it may be a sign of an underlying medical condition. Make an appointment to see your GP


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