Common Causes of Bad Breath

80-90% of the bad breath is due to dental or gum disease.

8-10% is caused by upper and lower respiratory disorders/disease such as tonsillitis, sinusitis and lung infections.

2-3% of cases are due to ‘systemic disease’.

Systemic disease includes, abnormalities of liver or kidney, endocrine disorders, diabetes mellitus, gastrointestinal disease – especially gastric reflux and hiatus hernia; leukaemia and other blood disorders; uraemia and metabolic disorders e.g. trimethylaminuria (TMAU) also known as fish odour syndrome because of the typical fishy smell of the breath. Some cancers and even HIV are associated with bad breath.

Odoriferous substances generated within the body are transported to the lungs via the bloodstream. If sufficiently volatile, they leave with the exhaled air and impart a fetid odour to the breath. This type of halitosis is also known as 'blood borne halitosis'. Sweat or urine may also be affected.

It is a popular misconception that bad breath mostly comes from the stomach. It will originate in the stomach on very rare occasions with very rare medical conditions or in very seriously ill patients.