Jennifer Fisher Wilson in The Smart Set:
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 wrinkle my nose wafted through his robes. My family always joked that we should give him Old Spice for Christmas.
We all emit body odors of some sort, of course, but some of us just cover them up better than others. I must have gone through a particularly stinky stage when, during my early adolescence, my mother took me to the grocery store and showed me where to find Tussy. The spicy-smelling, aqua-colored stick deodorant was the forerunner to Teen Spirit. Apparently, I needed it.