Everyone has bad breath from time to time, especially first thing in the morning. However, persistent changes in the smell of your breath can sometimes provide clues about what is happening inside your body. While bad breath is not a diagnosis on its own, it can be a sign that something deserves attention.
Here are some of the most common breath odours and what they may mean.
Rotten Egg Smell
A sulphur or rotten egg smell is one of the most common types of bad breath.
Possible causes:
• Poor oral hygiene
• Gum disease
• Tooth decay
• Bacteria on the tongue
• Tonsil stones
What to do:
Brush and floss twice daily, gently clean your tongue, stay hydrated, and visit a dentist if the smell persists or your gums bleed.
Fruity or Sweet Breath;
A fruity, sweet, or nail polish remover-like smell can be a warning sign of diabetic ketoacidosis, a serious complication of diabetes caused by very high blood sugar and ketone production.
Possible causes:
• Uncontrolled diabetes
• Prolonged fasting
• Very low carbohydrate diets
What to do:
If you have diabetes and develop fruity breath, excessive thirst, frequent urination, nausea, or confusion, seek urgent medical attention immediately.
Ammonia or Urine-Like Breath:
Breath that smells like ammonia may indicate your kidneys are not filtering waste products effectively.
Possible causes:
• Kidney disease
• Severe dehydration
• High protein diets
What to do:
Drink adequate fluids and arrange medical testing if this odour continues, particularly if accompanied by swelling, fatigue, or changes in urination.
Fishy Breath:
A fishy odour can occasionally be linked to a rare inherited metabolic disorder called trimethylaminuria, sometimes known as "fish odour syndrome." It may also occur with certain liver or kidney conditions.
What to do:
Consult your healthcare provider for appropriate evaluation if this is persistent.
Musty or Mouldy Breath:
A musty smell may occur in people with advanced liver disease due to the build-up of substances normally removed by the liver.
Possible causes:
• Liver disease
• Liver failure
What to do:
Medical assessment is recommended, especially if you also notice jaundice, abdominal swelling, or extreme fatigue.
Foul Breath with Sinus Symptoms
A persistent foul smell accompanied by a blocked nose or facial pain may point to a sinus infection or chronic postnasal drip.
Possible causes:
• Sinus infection
• Chronic allergies
• Nasal polyps
What to do:
Treat the underlying sinus condition and seek medical advice if symptoms last longer than 10 days or repeatedly return.
Faecal-Smelling Breath
Although uncommon, breath with a faecal odour may indicate a severe intestinal blockage, prolonged vomiting, or rarely a fistula between the bowel and stomach.
What to do:
Seek immediate medical attention, particularly if accompanied by severe abdominal pain or vomiting.
Sour or Acidic Breath:
A sour taste or acidic smell often occurs when stomach acid travels back into the oesophagus.
Possible causes:
• Acid reflux (GERD)
• Indigestion
• Hiatus hernia
What to do:
Avoid large meals before bedtime, reduce alcohol and fatty foods, maintain a healthy weight, and consult your doctor if symptoms are frequent.
Breath That Smells Like Decay:
A decaying odour can result from infections in the mouth, lungs, or throat.
Possible causes:
• Dental abscess
• Severe gum disease
• Lung infections
• Bronchiectasis
What to do:
Prompt dental or medical assessment is recommended.
Dry Mouth:
Sometimes the problem is not disease, but a lack of saliva.
Possible causes:
• Dehydration
• Mouth breathing
• Certain medications
• Sjögren's syndrome
Saliva naturally washes away bacteria. When your mouth becomes dry, bacteria multiply quickly and unpleasant odours develop.
What to do:
Drink plenty of water, chew sugar-free gum to stimulate saliva, and discuss medication side effects with your doctor if necessary.
When Should You Be Concerned?
Seek medical or dental advice if your bad breath:
• Persists despite good oral hygiene
• Is accompanied by pain, bleeding gums, or loose teeth
• Is associated with unexplained weight loss
• Comes with fever or persistent cough
• Is accompanied by excessive thirst or frequent urination
• Occurs with jaundice, swelling, or severe fatigue
The Bottom Line:
Your breath can offer valuable clues about your health. While many cases are simply caused by bacteria in the mouth or poor oral hygiene, unusual or persistent odours can sometimes signal underlying medical conditions affecting your teeth, sinuses, stomach, liver, kidneys, or metabolism.
If your breath changes suddenly or develops a persistent unusual smell, it is worth investigating rather than simply masking it with mints or mouthwash. Listening to these early warning signs may help identify health problems before they become more serious.
Written by Maryjayne Aria Author of Immune Health, Terrain and GcMaf
