Getty ImagesFrom Health magazine

Q. I've never had bad body odor—until now. What's up?

A. A quick primer on BO: Bacteria on our skin survive by munching on fat in our sweat; when they digest it, they produce the smell we know and loathe. So why more stink now? If you're perimenopausal or menopausal, fluctuating hormones may be sending your sweat glands into overdrive. Stress can also boost sweating.

In both cases, your perspiration should lessen in time—and the stink, too. For now, try an antiperspirant with the words "clinical protection" on the label—you'll get more active ingredients to help fight off sweat-happy bacteria.