Bad Breath (Halitosis): Causes, Treatment and When to See Your Dentist

1st August 2026

Have you ever worried that you might have bad breath?

You’re certainly not alone. Persistent bad breath, also known as halitosis, affects many people and can have a significant impact on confidence, relationships and everyday life. The good news is that, in many cases, bad breath can be successfully treated once the underlying cause has been identified.

What causes bad breath?

Although certain foods such as garlic, onions and spicy dishes can temporarily affect your breath, persistent bad breath is usually linked to your oral health.

Common causes include:

Gum disease

One of the most common causes of bad breath is gum disease. Bacteria collect around the teeth and gums, producing unpleasant-smelling compounds that can cause persistent bad breath.

Left untreated, gum disease can also lead to bleeding gums, gum recession and, eventually, tooth loss.

Plaque and bacteria

Your mouth naturally contains millions of bacteria. If plaque isn’t removed effectively by brushing and cleaning between your teeth, these bacteria multiply and produce odours.

Regular professional hygiene appointments can help remove plaque and tartar from areas that are difficult to clean at home.

Tooth decay

A decayed tooth can trap food and bacteria, creating an unpleasant smell and taste. Regular dental examinations allow us to detect decay early before it becomes a more significant problem.

Dry mouth

Saliva plays an important role in keeping your mouth clean by washing away food particles and bacteria.

A dry mouth can occur because of certain medications, dehydration, mouth breathing or some medical conditions, allowing bacteria to build up more easily.

Poorly fitting crowns, fillings or dentures

Old or damaged dental work may create areas where food and bacteria become trapped, contributing to bad breath. A dental examination can identify whether any existing restorations need attention.

Can bad breath come from somewhere other than the mouth?

Yes.

While most cases of bad breath originate in the mouth, it can occasionally be linked to:

Sinus infections
Tonsil stones
Acid reflux
Certain medical conditions
Some medications

If your dentist feels your oral health is not the cause, they may recommend that you speak with your GP for further assessment.

How can I improve my breath?

There are several simple steps you can take:

Brush your teeth twice a day using fluoride toothpaste.
Clean between your teeth every day using floss or interdental brushes.
Gently clean your tongue, where bacteria often collect.
Stay well hydrated.
Attend regular dental examinations and hygiene appointments.
Replace your toothbrush every three months or sooner if the bristles become worn.

Avoid relying solely on mouthwash or breath mints, as these often mask the problem rather than treating the underlying cause.

When should I see a dentist?

If you’ve noticed persistent bad breath that doesn’t improve with good oral hygiene, it’s worth arranging a dental examination.

Our dentists can identify the cause and recommend the most appropriate treatment, whether that’s improving your oral hygiene routine, treating gum disease, repairing a tooth or referring you for further investigation if necessary.