Sometimes, the type of smell is a symptom of very specific problems.
For example, the "smell of rotten" may indicate a tooth decay, gum disease or sinusitis. A "fruity odor" could be a symptom of diabetes mellitus.
The smell of cheese "in a child usually warn of the presence of a foreign body in his nose. A smell of urine can be a symptom of renal failure.
Other causes of bad breath include medical conditions or chemical origin. For example, the dysfunction of the liver, lung disease and respiratory disease (lung infections). There are also drugs that can cause odors; The dryness in the mouth can be caused by more than three drugs, including antidepressants and antihistamines.