NPR begins a celebration of sweat — what it's made of, where it comes from and what it smells like. Spoiler alert: most of the time it doesn't have any smell at all.

There are many reasons why sweat may smell like ammonia, from diet to underlying health conditions. We explore the potential causes, treatments, and more.

Sweat glands can also become overactive and lead to the overproduction of sweat. This condition is called hyperhidrosis, and it can be a nuisance. Talk to your doctor about treatment for excessive ...

But, in fact, there is a stinky form of sweat. In addition to ecrine glands, Xu says there's something called apocrine glands. XU: They kind of exude a certain more protein-rich sweat.