We’ve all experienced it — that uncomfortable moment when you wonder if your breath is less than fresh. Bad breath, or halitosis, is a common issue that affects people of all ages. While it’s often temporary and harmless, persistent bad breath can signal underlying dental or health problems.
The good news? Most causes of bad breath are easy to fix with the right habits and a bit of professional guidance. Here are the seven most common causes — and simple ways to freshen your breath for good.
1. Poor Oral Hygiene – The #1 Cause of Bad Breath
The most frequent culprit behind bad breath is poor oral hygiene. When food particles remain in the mouth, bacteria break them down, releasing foul-smelling sulfur compounds. Plaque buildup on teeth, tongue, and gums only makes things worse.
The fix:
Brush at least twice a day using fluoride toothpaste, and don’t forget your tongue — bacteria often accumulate there. Floss daily to remove food particles between teeth, and rinse with an antibacterial mouthwash to kill odour-causing bacteria.
Pro tip: Replace your toothbrush every 3 months, and visit your dentist regularly for professional cleanings.
2. Dry Mouth (Xerostomia) – When Saliva Stops Flowing
Saliva plays a vital role in washing away food particles and neutralising acids. When saliva production decreases — often due to dehydration, medication, or sleeping with your mouth open — dry mouth occurs, allowing bacteria to thrive.
The fix:
Stay hydrated throughout the day and chew sugar-free gum to stimulate saliva flow. Avoid caffeine, alcohol, and tobacco, which can worsen dryness. If dry mouth persists, your dentist may recommend saliva substitutes or a specialised mouth rinse.
3. Certain Foods and Drinks – Garlic, Coffee, and More
Some foods naturally cause strong odours that linger long after eating. Garlic, onions, coffee, and spicy foods release sulfur compounds that enter your bloodstream and are exhaled through your lungs — making mints and mouthwash only temporary solutions.
The fix:
Limit odorous foods before important meetings or social events. After consuming them, rinse your mouth with water, chew parsley or sugar-free gum, and brush your teeth when possible.
Bonus tip: Eating crunchy fruits and vegetables like apples, celery, and carrots helps naturally clean your teeth and freshen your breath.
4. Tobacco Use – Smoking and Vaping
Tobacco is a double offender: it dries out your mouth and leaves behind strong, lingering odours. Smokers are also more prone to gum disease, another major cause of chronic bad breath.
The fix:
The only real solution is to quit smoking or vaping. Your breath, gums, and overall health will improve dramatically. Dentists can provide resources or refer you to smoking cessation programs that make the process easier.
5. Gum Disease – The Hidden Source of Persistent Odour
If your bad breath won’t go away even with good hygiene, gum disease (periodontal disease) could be the cause. It develops when plaque hardens into tartar and irritates the gums, leading to infection and a persistent foul smell.
The fix:
Visit your dentist for a professional cleaning and gum evaluation. Early-stage gum disease (gingivitis) can be reversed with better hygiene and treatment. Advanced cases may require scaling and root planing (deep cleaning) to remove bacteria below the gum line.
6. Medical Conditions – Beyond the Mouth
Sometimes, chronic bad breath is linked to underlying medical conditions. Sinus infections, tonsil stones, diabetes, acid reflux (GERD), liver disease, or kidney problems can all produce distinctive odours due to bacterial imbalance or chemical buildup in the body.
The fix:
If dental treatments don’t solve the problem, see your GP or specialist. Managing the underlying condition usually resolves the bad breath as well. Always mention persistent halitosis during medical check-ups.
7. Low-Carb Diets and Fasting – The “Keto Breath” Effect
Diet trends like keto or intermittent fasting can cause temporary bad breath. When your body burns fat for energy instead of carbs, it releases ketones — chemicals that can create a fruity or metallic odour known as “keto breath.”
The fix:
Stay hydrated, chew sugar-free gum, and maintain proper oral hygiene. Over time, as your body adjusts to the diet, the odour usually subsides.
