1. Your brain's in pain.
When you're stressed, your hormones set off a series of neurochemical events in your brain that stimulates your nerves and causes your blood vessels to swell. The result: tension headaches and migraines. There are ways to cope, however. Studies have shown that people who practice relaxation and stress-management techniques cut the number of headaches they have by as much as 35 to 50 percent.
2. Your stomach churns and burns.
You've been waiting in the check-out line at the grocery store for 20 minutes, you're late for preschool pickup, and you've spilled coffee all over your new pants. By the time you get back in the car, your stomach is a queasy mess. Those little daily hassles can actually disrupt gut function and cause digestive problems just as much as major life changes can. "Anxiety and stress can cause the body to produce more digestive acid, which leads to heartburn. They can also slow the emptying of food from the stomach, which causes gas and bloating, and may even increase the number of times your colon contracts, leading to cramping and diarrhea," explains Deborah Rhodes, M.D., a consultant in internal medicine at Mayo Medical School, in Rochester, Minnesota.
3. You sneeze up a storm.
Does it seem as if you come down with a cold every time you have to give a presentation at a PTA meeting? It isn't just your imagination: Stress suppresses the immune system, making it easier for you to get sick. In a study at Carnegie Mellon University, in Pittsburgh, researchers surveyed volunteers about what was going on in their lives, and then infected them with a cold virus. The men and women coping with stresses ranging from a bad marriage to unemployment were twice as likely to get sick as those with fewer problems.
4. You're up all night.
The day is done, but your mind's still buzzing—leaving you to toss and turn in bed. You aren't the only one lying there wide awake. "Stress is the number-one cause of sleep deprivation and insomnia," says James Maas, Ph.D., author of Power Sleep. "That lack of shut-eye, in turn, makes you irritable and anxious, decreases your ability to fight infection, and impairs your ability to concentrate." Sleep problems also create a vicious circle: Once you're sleep deprived, your threshold for dealing with everyday problems is even lower—keeping you stressed out and making it more difficult to sleep the following night.
5. You pack on the pounds.
"When your body perceives stress, it assumes you need physical energy to protect yourself and releases adrenaline and cortisol," explains Pamela Peeke, M.D., an assistant professor of medicine at the University of Maryland School of Medicine, in Baltimore. "These hormones trigger the sensation of being hungry—which women, especially, respond to by eating fats and carbs." (Now you know why you head for the vending machine every time your boss gives you another impossible deadline.)
6. Your back attacks.
While the physical rigors of being a parent—lugging baby gear, racing after small children—can contribute to backaches and muscle twinges, research shows that most chronic back pain is caused by psychological stress. "Tension triggers the sympathetic nervous system to reduce blood flow to the muscles, which makes them prone to spasms," says Douglas Johnson, M.D., coauthor of Back Sense. To make matters worse, people tend to hunch over and tense their shoulder and neck muscles when they're anxious—exacerbating back problems.
7. Your skin is a mess.
Freak out, and the next thing you know you might break out. "Stress can affect the levels of the male-like hormone called androgen in the body, which trigger the sebaceous glands to produce more oil, leading to clogged pores and pimples," says Diane Berson, M.D., an assistant professor of dermatology at Weill Medical College of Cornell University, in New York City. Stress also stimulates the skin's nerve endings, causing flare-ups of skin conditions ranging from eczema to psoriasis. Even cold sores can be blamed on too much tension. "Stress wears down your immune system, enabling the viruses that cause these sores to reactivate," says Rena Fortier, M.D., a dermatologist with Long Ridge Dermatology, in Stamford, Connecticut.
8. Your cuts and scrapes just won't go away.
A study from Ohio State University, in Columbus, found that psychological stress can make injuries take longer to heal. In the study, doctors gave women who were caring for chronically ill relatives and women in a control group small skin wounds on their forearms. Despite receiving the exact same methods of cleaning and bandaging, the caregivers' wounds took an average of nine days longer to heal. Just think what mellowing out could do for all those unsightly nicks from shaving your legs.
9. You forget your kids' names.
The babysitter's late, you're due at a parent-teacher conference in five minutes, and your preschooler just tried to flush the cat down the toilet. You try to shout at him to stop, but you draw a blank—or call him by his sister's name. Have you finally lost it for good? Not quite. "High levels of the stress hormone cortisol can temporarily impair your ability to recall well-known information," explains James McGaugh, Ph.D., director of the Center for Neurobiology of Learning and Memory at the University of California at Irvine. Even more depressing: Research shows that chronic stress may actually damage brain cells.
10. You may have a harder time getting pregnant. "Stress negatively impacts every organ of the body, including the reproductive system," says Parents adviser Alice Domar, Ph.D., author of Conquering Infertility. "The more stressed and depressed a woman is, the less likely she is to conceive." There's good news though: Learning how to use relaxation techniques and stress-coping skills to reduce your psychological distress can boost your chances of getting pregnant. "Not only does learning how to control stress help you conceive, but it also makes you a healthier, happier person," Dr. Domar says. And let's face it, what mom doesn't want that?