THE SCIENCE OF HORMONES

Being hormonal is a good thingthese tiny molecules keep your body humming along! But if you have too much (or not enough) of any, there are ways to rebalance your system.

- KAITLYN PIRIE

Everything from your metabolism to your fertility is controlled by hormones. There are more than 50 hormones in the human body, and some are really good at one job, while others multitask.

Hormones are messengers. "They are little molecules that are produced in different organs," says Mihail Zilbermint, M.D., an associate professor of clinical medicine at Johns Hopkins University School of Medicine and the chief of endocrinology, diabetes, and metabolism at Suburban Hospital in Bethesda, MD. "They circulate in our bodies and give signals and directions to produce other substances that are responsible for keeping our bodies up to speed and balanced." For a hormone to do its job, it needs to make its way to cells designed to receive it, as a key fits a lock. For instance, the hormone insulin can do its job of removing glucose from the bloodstream only if receptors in muscle, fat, and liver cells receive it. But hormones don't work alone-insulin, like many, works as part of a team. Another hormone, glucagon, ensures that too much sugar isn't taken from the blood.

Sound complicated? It is. The endocrine system is the network of hormones (and the glands and organs that produce them) that keeps the body functioning. We can't explain it all here (endocrinologists spend years learning it!), but here are highlights of important hormones, along with what you can do to keep certain ones at proper levels and how to know if something is awry.

INSULIN

"Every time we eat, beta cells in the pancreas release insulin to help the body use or store blood glucose, which is the sugar we get from food," says Dr. Zilbermint. When levels of insulin get out of whack, the result can be type 1 or type 2 diabetes, which together affect more than 37 million Americans.