You can smell sickness on someone's breath.
Many illnesses and diseases can cause a persons breath to smell different.
Common sickness and diseases that can cause a persons breath to smell different include.
Diabetes.
Kidney failure.
Liver disease.
Liver disease can cause a persons breath to smell like garlic, rotten eggs or musty.
Kidney failure can cause a persons breath to smell like urine or ammonia.
Diabetes can cause a persons breath to smell like rotten apples or fruity.
Your breath also contains gassy compounds which move from your organs through your bloodstream into your lungs that can cause your breath to smell.
Having serious liver disease can make your breath smell musty or like garlic and rotten eggs.
Compounds which are transported through the blood can also be released through your sweat glands.