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Actually, scratch that. Your endocrine system—the network of glands that produces and regulates your hormones—is really in charge, says Cynthia Stuenkel, MD, a clinical professor of medicine at the University of California, San Diego, and a spokesperson for the Endocrine Society’s Hormone Health Network.
Working in concert, the glands that make up your endocrine system—your pancreas, thyroid, ovaries, and others—manage everything from your mood, appetite, and energy levels to your reproductive cycle and immune system. Your glands do all that by releasing and regulating hormones, which are effectively chemical messengers that tell the different systems in your body how to behave, Stuenkel explains.
You’re probably familiar with estrogen and testosterone—the primary female and male sex hormones. But there are many others that serve essential functions. Here are 7 you should be familiar with, why they matter, and how to tell if they’re out of whack.
What it does: The thyroid gland’s namesake hormone is your body’s “metabolic thermostat,” Stuenkel says. From your appetite and energy levels to the timing and strength of your periods, your thyroid plays an important role in many different internal functions. It’s also the most common source of endocrine disorders in women, Stuenkel says. (Feel better starting today with Rodale’s The Thyroid Cure, a new book that’s helped thousands of people finally solve the mystery of what’s ailing them.)
Signs it’s off: If your thyroid gland produces too much of this hormone, you may overeat, feel nervous or agitated, suffer bone loss or heart palpitations, or feel hot all the time. Produce too little, and “everything slows down,” Stuenkel explains. Your thinking grows foggy, your energy level plummets, and your menstrual cycles may be longer and heavier, she says. A thyroid-stimulating hormone (TSH) test can help a doctor assess your levels.
What it does: It’s an important pregnancy hormone that helps your womb accept and adapt to the presence of sperm. Progesterone rises and falls dramatically during the course of your menstrual cycle, says Louann Brizendine, MD, a professor of neuropsychiatry at the University of California, San Francisco, and author of The Female Brain. “We sometimes call it the valium hormone because when it’s very high—around day 19 of your cycle—you feel very mellow, you sleep well, and you eat more,” Brizendine says. Before thisprogesterone peak—or around days 10 to 14 of your cycle—a milder uptick in progesterone “energizes thinking and behavior,” she explains.
Signs it’s off: Pregnancy complications, irregular or abnormal periods, and low energy or weight gain could all be the result of progesterone issues. A simple blood test called the PGSN or “the progesterone test” can check your levels, Brizendine says.
What it does: By regulating your body’s circadian clock, melatonin helps you get to sleep at night, and also plays a role in your appetite and energy levels, says Michael Grandner, PhD, director of the Sleep and Health Research Program at the University of Arizona.
Signs it’s off: You feel sleepy during the day and energized late in the evening—the time your body should be settling down and preparing for sleep. Your appetite and energy levels may also surge and flag at odd times, Grandner says. A blood or urine test can tell a doctor if you’re truly deficient in melatonin. But for most people, sticking to a consistent sleep, wake and meal schedule can help get melatonin—and your body’s circadian clock—back on track.
What it does: It helps regulate your blood, organs, and bone calcium levels, Stuenkel explains. It also helps your body break down and metabolize vitamin D.
Signs it’s off: Hand or foot spasms and an irregular heartbeat are signs it’s low, Stuenkel explains. Dehydration, kidney stones, and osteoporosis are linked to overproduction of parathyroid. A blood test can tell your doctor if you’re making too much or to little of it.
What it does: Yes, it spikes when you’re stressed. It also assists with memory formation, helps control your blood sugar levels, keeps your body’s salt-to-water ratios in balance, and promotes or limits inflammation, Stuenkel says.
Signs it’s off: A flushed, red face, hair loss, fine hairs covering your face, osteoporosis, and menstrual cycle irregularities are all signs your cortisol levelsmay be wonky, Stuenkel says. A blood test can tell your doctor what’s up.
What it does: This hormone fires up your “feed me” urges. It also tells your gut to start making the digestive acids and juices that will allow it to break down the foods you eat.
Signs it’s off: You’re hungry again very soon after eating, or you don’t feel satisfied even after chowing down excessively. Too little sleep and too much stress can both throw off your ghrelin levels. Ghrelin issues can also stem from carb- or sugar-heavy diets, suggests research from the British Journal of Nutrition and elsewhere.
What it does: It allows the cells in your muscles, fat, and liver to absorb the glucose—or energy—circulating in your blood, Stuenkel explains. This energy comes from the foods you eat.
Signs it’s off: Too much or too little insulin screws up your body’s ability to manage blood glucose. At first, this could result in extreme thirst, peeing all the time, or weird skin patches. Later, it can develop into type-1 or type-2 diabetes. A blood glucose test (A1C) can identify insulin issues.