“Halitosis” is the medical term for bad breath. But it goes beyond a garlicky smell or ‘coffee breath.’ It refers to a persistent unpleasant smell in the breath that doesn’t go unnoticed. The odour can come from your mouth or teeth, or may even be a sign of an underlying medical condition. 

We all worry about having bad breath at some point. It’s estimated that around 50% of adults have had halitosis in their lifetime. Causes range from poor dental hygiene to periodontal disease. Understanding these causes can help you find a permanent solution. 

What Is Halitosis? 

Halitosis is the medical term for persistent bad breath. Unlike temporary odours caused by food, drink, or morning breath, halitosis lingers and often indicates an underlying issue in the mouth, teeth, gums, or elsewhere in the body. The smell may be noticeable to others and can range from mildly unpleasant to strong and foul. 

While halitosis simply means bad breath, it’s usually reserved for severe cases. In fact, halitosis can have several distinct smells, including: 

• Fruity breath — linked to diabetes 

• Foul, faecal smell — caused by prolonged vomiting or bowel obstruction 

• Ammonia or fishy smell — linked to kidney failure 

Symptoms of Halitosis 

The main symptom is a persistent unpleasant smell on the breath, but it can also be accompanied by: 

• A bad taste in the mouth 

• Dry mouth or a sticky feeling on the tongue 

• Coated tongue (white or yellowish layer) 

• Thick saliva 

• Post-nasal drip or frequent throat clearing 

• Mouth sores or gum bleeding (if linked to gum disease) 

Causes of Halitosis 

Poor Dental Hygiene 

The most obvious cause of bad breath is not brushing your teeth. If you fail to brush, floss, and thoroughly clean your teeth and mouth, food particles begin to decay in your mouth. 

Bacteria can also accumulate, leading to plaque buildup, tooth decay, and periodontal disease (see below). 

Certain Foods and Drinks 

Foods like onions, garlic, or coffee are renowned for giving you bad breath. These foods can continue to cause an odour for up to 72 hours after consumption. While it’s not a serious cause, it can be unpleasant for people around you. 

Smoking 

Smoking dries out the mouth and leaves lingering odours on the breath. 

Periodontal Disease 

Periodontal disease (gum disease) is a serious cause of halitosis. It occurs when plaque builds up on the teeth, hardening into tartar. Small pockets begin to form around the teeth and below the gumline, leading to bacterial accumulation and a foul smell. 

Dry Mouth 

If you don’t produce enough saliva, your mouth doesn’t get cleaned. Saliva helps clean your mouth, washing away bad smells.  

Oral Conditions 

Several oral and sinus conditions can lead to halitosis, including sinus infections, chronic bronchitis, postnasal drainage, and chest infections.  

Diseases 

Specific types of halitosis are linked to underlying medical conditions. These include: 

• Kidney disease or kidney failure 

• Liver disease or liver failure 

• Diabetes 

• Sleep apnoea 

• Gastro-oesophageal reflux disease (GERD)  

GERD and other forms of regurgitation are a common cause of halitosis. Not only do they lead to an unpleasant smell, but patients also describe a sour, tangy taste. 

Diagnosing Halitosis 

Most cases of halitosis don’t require any medical intervention. Your doctor will likely take a medical history and inspect your mouth. Often, the only advice is a change in dental hygiene and lifestyle recommendations. 

If your halitosis is persistent or linked to other symptoms, further investigations might be necessary. These can include: 

• Oral swab or culture. Checks for bacterial overgrowth. 

• Periodontal probing. Measures gum pocket depth for gum disease. 

• Blood tests. Screens for diabetes, liver disease, or kidney disease. 

• Urinalysis. Checks kidney function. 

• Endoscopy. Investigates possible GERD and other upper GI issues. 

If your halitosis is linked to heartburn symptoms, get in touch with The Functional Gut Clinic. We offer comprehensive testing for heartburn, regurgitation, and halitosis, finding the underlying cause behind your symptoms.  

How to Treat Halitosis 

Halitosis is relatively simple to treat. Thoroughly brushing your teeth twice per day alongside flossing, interdental brushes, and mouthwash will solve the majority of cases. 

Other lifestyle changes include: 

• Stop smoking

• Avoid certain foods 

• Chew sugar-free gum 

• Clean dentures daily 

• Eat a healthy, balanced diet 

If a medical cause is identified, then specific treatment is recommended. This could be dental work to fix any cavities or gum recession, or more intensive treatments for diabetes, kidney disease, and reflux. Your doctor may prescribe antibiotics for a sinus infection or artificial saliva if you have persistent dry mouth. For reflux, they might recommend medications that reduce stomach acid, such as proton pump inhibitors (PPIs) or H2 blockers.