Raleigh, N.C., businessman Buddy Howard used to feel his heart race and dread set in every time he thought about driving up profits at his equity research firm or was faced with an unwieldy project that seemed impossible to complete. Then his 11-year-old daughter developed anorexia—and he suddenly learned the difference between stress and stress. "Nothing comes close to the stress you feel as a parent when you're afraid that your child is going to die," says the 50-year-old father of two, who, seven years later, gets energized by the same deadline crunches that used to paralyze him. He now breaks large projects into discrete tasks that provide daily victories—the same bite-by-bite, pound-by-pound process his daughter used to overcome her eating disorder. And he's altered his perspective on bigger earnings, focusing on the rush of the challenge and blotting out the fear of failure.
Stress has certainly earned its bad reputation, given the wreckage it causes: headaches, stomach pain, high blood pressure, insomnia, and mind freeze reminiscent of a crashing laptop. But it also has an unheralded upside. In normal doses, adrenaline and other "fight or flight" hormones improve performance and seem to even protect health. They increase alertness and motivate you to get things done by quickening your heartbeat, improving blood flow to the brain, and enhancing vision and hearing. And in small amounts, studies suggest, they boost the immune system and may protect against age-related memory loss by keeping brain cells active. University of Texas researchers recently found that those engaged in challenging and creative work enjoy better health—an advantage equivalent to being nearly seven years younger. "Your goal shouldn't be to get rid of stress," contends Esther Sternberg, a researcher at the National Institutes of Health and author of The Balance Within: The Science Connecting Health and Emotions. Rather, she says, you should aim for "the appropriate stress response."
Extremely agitated. Getting the calibration just right can be tough, but it's achievable: As Howard discovered, it's often a matter of changing one's perception of a challenge. Plenty of Americans have yet to figure out how. According to a recent survey by the American Psychological Association, nearly half say their level of stress has increased over the past five years, and fully one third routinely experience extreme agitation.
The problem with overwhelming stress? In the short term, the rush of stress hormones can make people less productive, even mentally paralyzed. Think writer's block. When the overload becomes chronic, heart disease, depression, and an impaired immune system can result. An estimated 50 to 80 percent of people who develop depression have faced a major stressful life event, like a divorce or job firing, during the preceding three to six months and most likely have produced an excessive amount of the stress hormone cortisol. An October study published in the Journal of the American Medical Association found that heart patients battling chronic job strain were twice as likely as their more relaxed peers to have another heart attack. And researchers have been aware for some time that overanxious folks exposed to cold viruses are more apt to end up sick than those who aren't.
"We think the system stops working appropriately when it's constantly turned on," says Sheldon Cohen, a professor of psychology at Carnegie Mellon University who first discovered the link between colds and stress. Chronically elevated cortisol levels lead to more colds and infections; depleted levels can cause an overactive immune system—and autoimmune diseases like rheumatoid arthritis.
The ultimate goal is to hit a stress response appropriate for a given situation: You want to be in low gear when you're, say, watching TV, medium when you're doing car pool, and high—but not overdrive—when you're under a deadline crunch. High gear is what Sternberg calls the peak of the "stress response rainbow," or the point where you're at your most productive, able to focus on the task at hand with minimal distractions. Most likely, you're sent into this zone by an optimal level of adrenaline, cortisol, and other hormones that increase your pulse, reduce peripheral vision, and improve blood flow to the brain.
Biology undoubtedly plays a role in how easily you hit the target: A study published last year in the journal Cell found that mice that adapted poorly after being put in a cage with bigger, more aggressive mice produced larger amounts of stress-related brain chemicals than those that adapted well. But modifiable beliefs and expectations factor in, too. Expecting that your life will be unchanging, for example, is bound to make you react badly to dropping house values and a child's academic reversals, says psychologist Robert Rosen, author of Just Enough Anxiety, a new book that explains how anxiety can be a key to success in the workplace. "Buddhists have this idea that every time we breathe, the world changes," Rosen says. A philosophy of acceptance allows them to make peace with what they can't control—like an earthquake, inflation, or an oppressive political regime.