Sometimes the smell of body odor means more than just “Wash me!” A person whose sweat starts to smell fruity may have developed diabetes, and an ammonia smell may indicate liver or kidney disease. Odor of rotting fish may signal trimethylaminuria — a rare syndrome caused by a defective gene that prevents people from metabolizing trimethylamine, a natural byproduct of digestion of certain foods like saltwater fish, eggs, and liver.

Body odors have a way of making a lasting impression, even when they don’t signal illness and even when we try ignore them. I’ll never forget the powerful scent emanating from Father Brady, the Irish priest at the church where I grew up. He never looked sweaty, but whenever he would lean over to shake my hand with his own squat, papery one, a smell that made me… More…