(FORTUNE Magazine) – For John Haughom, it started about two years ago.

The stress. Not the mundane, I-have-to-pick-up-the-kids-but-my- meeting-is-running-late-and-will-I-ever-get-that-report-done-by- morning? stress. But stress with a capital "S." When picking up the kids and late meetings and morning deadlines become just too much to handle.

Before the summer of 2000, the 54-year-old senior VP for infotech at PeaceHealth, a private network of hospitals in the Pacific Northwest, could accomplish just about anything at work. He would start his day by 6 a.m., sending e-mails and returning voice messages from home. By 7:30, when he got to work, the meetings would begin. Forget lunch: Soon Haughom would be lost in the dreaded phone/meeting/e-mail triangle (Bermuda's less glamorous cousin). He'd stumble out of the office around 7 p.m. in time to catch a quick bite with his wife, Frances, before heading into his home office, where he worked until 11 p.m. every night. "I could move mountains if I put my mind to it," he says of those days. "That's what good executives do."

But that summer Haughom found he couldn't move them anymore. He began to lie in bed and replay his day at work, sleeping only a couple of fitful hours a night. At the office he began snapping at people. "He just wasn't himself," says his boss, PeaceHealth CEO John Hayward. On the phone with his wife one morning, Haughom broke down. "Frances," he began. His voice was shaky, his heart was racing, and he couldn't stop sweating. The phones in his office were ringing as they did every morning, but he ignored them. "I've got to do something," he told her. "I can't go forward."

A couple of days later Haughom checked himself in for a three-week stay at the Professional Renewal Center, an in-patient clinic 30 miles outside Kansas City that helps executives deal with addictions, depression, or, in his case, stress. Afterward Haughom spent two more months at home before he was ready to return to work. "It was amazingly hard," he says of his ordeal. "Some people have alcohol problems. Stress was my problem."

He is far from alone. A host of new studies and plenty of anecdotal evidence show that stress in the workplace is skyrocketing. Blame it on the economy, terrorism, the new 24/7 workweek, corporate scandals--did we mention the economy? Whatever the cause, stress levels are at record highs. "People are absolutely nuts, stressed off the map," says Dr. Stephen Schoonover, author of Your Soul at Work and head of the executive development firm Schoonover Associates, which helps executives combat stress and balance their lives. He has seen his practice surge 30% over the past two years. Like each of the dozens of stress experts we talked to--MDs, psychiatrists, therapists, workplace gurus--Schoonover says, "I've never seen it this bad."

The statistics are startling. According to a new study by the federal government's National Institute for Occupational Safety and Health, more than half the working people in the U.S. view job stress as a major problem in their lives. That's more than double the percentage in similar studies a decade ago. The number of people who called in sick due to stress has tripled in the past four years. Fully 42% of employees--double the percentage a year ago--think their co-workers need help managing stress. In an annual survey released last month by workplace research firm Marlin Co., 29% of respondents put themselves in the highest category of stress--extreme or quite a bit--the highest percentage in the poll's six-year history. And it's not just here in the U.S. This year the European Community officially dubbed stress the second-biggest occupational-health problem facing the continent.

Ten years ago--the last time experts warned that stress was out of control, in part because of a shaky economy--Dr. Jim Quick, president of the International Stress Management Association and a professor at the Baylor School of Medicine in Texas, used to say that we were not more stressed than we had been; people were just becoming more aware of their stress. "I don't think that is the case this time around," Quick says. "We have a problem." Dr. Scott Stacy, clinical program director of the Professional Renewal Center, estimates that the average executive will skate dangerously close to burning out two or three times in his career. And the price tag is high. The American Institute of Stress, a research group, estimates that stress and the ills it can cause--absenteeism, burnout, mental health problems--cost American business more than $300 billion a year.

What's notable about today's wave of stressed-out workers is that it rises all the way to the top. Lack of control is generally considered one of the biggest job stressors, so it used to be thought that middle managers carried the brunt: Sandwiched between the top and the bottom, they end up with little authority. Powerful CEOs were seen as the least threatened by stress. But in today's tough economy, top executives don't have as much control as they used to. Now that the corner suite has become scandal central, senior executives are complaining that they can't get anyone to listen to them--the very same stressor cited most commonly by those at the bottom of the ladder. Then there's the "stress of success": CEOs who perform exceptionally well are often expected to do just as well in every other aspect of their lives, an impossible standard to meet.

"Stress is just part of the job," says Alexandra Lebenthal, CEO of Wall Street securities firm Lebenthal & Co. The past year has been particularly stressful for Lebenthal and her staff: The 75-year-old, family-run firm was acquired by the MONY Group a month after the Twin Towers crumbled outside its windows. "Fortunately or unfortunately, [stress] is part of our character building," Lebenthal says. "But there is a moment when you think, I don't need any more character building. What I need is a vacation."

But if you think that going on vacation is hard--and studies show that 85% of corporate executives don't use all the time off they're entitled to--seeking treatment for stress is even harder. Being able to handle stress is perhaps the most basic of job expectations; it is at the core of not just doing good work but doing work, period. So among the corporate elite, succumbing to it is considered a shameful weakness. "I hear a lot of people saying, 'It's tough.' But executives don't use the 's' word," says Manhattan executive coach Dr. Dee Soder. While some executives may talk openly about their problems with alcohol, sex addiction, depression, and dyslexia, stress has become the last affliction that people won't dare admit to. Most senior executives approached by FORTUNE who are undergoing treatment for stress--and even many who aren't--refused to talk on the record about the topic. "Nothing good can come out of having your name in a story like this, not in these times," one CEO said through his therapist.

"Typically the people who come to me think that their problem is unique. It's not," says Dr. John Arden, a stress therapist in San Francisco and author of Surviving Job Stress. But stress does manifest itself differently with everyone. For one CEO, says a doctor who treated him, stress causes the right side of his body to turn "numb and tingling" whenever his car pulls into the company parking lot. For the president of a financial services firm, each new wave of corporate scandals prompts obsessing about the worst possible outcome of his every decision. Will that expenditure come back to haunt me? Is my staff honest? Should I send this e-mail? Then there are those senior executives suffering from bladder control problems (really)--and even more who have lost their sex drive completely (yes, stress can do that). There is no medical definition of stress, but it is directly linked to cardiovascular disease, depression, impaired immune disorders, alcoholism, drug addiction--plus the everyday headaches, back spasms, overeating, and other annoying ailments your body has developed in response. "Don't let anyone tell you it is just in your head; it is in your body too," says Quick.

Consider the case of Naomi Henderson, who was paralyzed by her stress--literally. The 58-year-old CEO of RIVA, a small market-research firm in Bethesda, Md., often put in 120 hours a week at the office and slept two hours a night. A perfectionist who was unable to delegate, she couldn't turn down any request for her time and so was doing, well, everything. And she hadn't taken a vacation in years. "I felt like a bowl of chocolate mousse, and everyone had a spoon but me," she says.

After keeping this pace for several weeks straight, one night Henderson woke up to go to the bathroom and couldn't move her legs. She stared down at her limp limbs, blinking in disbelief. Her mind began fixating on the most improbable of causes: Polio? Some new disease she hadn't heard of yet? In a panic, she screamed for her husband. He scooped her up and drove her to the hospital, carrying her--still in a bathrobe and with tears streaming down her face--into the emergency room. The diagnosis: stress. The doctor put her on bed rest 14 hours a day for six weeks.

Though traumatic, the incident did not get the competitive executive to change her ways. A few years later, shortly after she learned that her partner was leaving the business, it happened again: the temporary paralysis, the ER, the bed rest. What did eventually push Henderson to seek help was her ballooning weight. The doctor told her that stress (specifically, the binge eating she was using to cope with it) was again the cause of her problems. At first, "I was pissed off," she says. "I didn't want to hear about stress; it is not going to go away. Isn't there a salad thing that can solve my problem?"

But under the care of Dr. Pamela Peeke, who treats a number of fortune 500 executives, Henderson got better. She did it by fundamentally reorganizing how she lives her life. "It's mental aerobics," says Peeke, a professor of medicine at the University of Maryland. "Top athletes do stuff like this for their bodies; the highest execs need to do it for their minds."

Henderson now has a timer on her watch that beeps on the hour to remind her to stop whatever she is doing and take a break for stretches and deep breathing. She forces herself to take short naps to replenish her energy during the day, particularly on airplanes, where she has banned work so she can doze. She has mastered the art of the polite no: "Thanks so much for asking, but I won't be able to meet that request." And hanging over her desk is a prescription written by Dr. Peeke: "Must have ten-day vacation 3x a year." Henderson, who required weekly sessions (at $150 an hour) with Peeke for two years, now sees the stress doc quarterly. Says Henderson: "I'm clear that I'm never going to be in a stress-free mode. The business of business is about stress. But I will become the master of stress management."

How can you tell if your stress--or that of someone who works for you--is getting out of control? Telltale signs include irritability, forgetfulness, social isolation, and sudden changes in appearance, such as disheveled clothing and weight gain (see the quiz). Under great stress, everyone's dominant trait becomes even more pronounced. So if you're detail-oriented, you become a micromanager; if you're a private person, you withdraw from your colleagues; if you're upbeat and outgoing, you become hyperactive. Which means that stress won't help you win any Manager of the Year awards.

Not all stress is bad, experts say. Some people thrive under stressful conditions. In corporate America, especially, people often rise to the top by learning how to overcome stress. It is when stress overwhelms you that it becomes a problem. And that breaking point is different for each of us. "Stress is like a violin string," says Dr. Allen Elkin of the Stress Management and Counseling Center, a clinic in New York City. "If there's no tension, there's no music. But if the string is too tight, it will break. You want to find the right level of tension for you--the level that lets you make harmony in your life."

That means stress management. It virtually didn't exist a decade ago; now it's a $10 billion industry. It might involve anything from breathing techniques to psychotherapy--even stints at in-patient clinics like the one PeaceHealth exec Haughom attended (see box, this page). And it just might be a lifelong process. Almost two years after the mountains became immovable for Haughom, he says he still has to make a conscious effort to keep his stress under control. "The situation hasn't changed," he says. "But I have changed."

During meetings at work, Haughom now brings up issues the moment they start to bother him rather than internalizing them. After particularly intense meetings, he makes sure to take a couple of deep breaths to calm himself before moving on to the day's next order of business. When he comes home at 7 p.m., his wife no longer immediately asks why he's so tense. He isn't. Gone, too, are the early-morning e-mail marathons. Instead he has been focusing more on family, enjoying, he says, the best relationship he has had in years with his four sons, ages 18 to 24. At night there's no more tossing and turning: "I sleep like I did when I was 12 years old."

Haughom's stint away from the office to deal with stress hasn't hurt his career either, insists PeaceHealth CEO Haywood--though Haywood admits that since his company is in the health-care industry, he may be more understanding than, say, his peers on Wall Street. "We don't dwell on it," says Haywood, who encouraged Haughom to take the time he needed. "Part of it is the guilt, because you wonder how much the job is contributing to the problem. But he is doing better now than ever." Last month, Haughom was named one of the nation's top ten health-care IT innovators by a prestigious panel of national health-care leaders.

Favoring recovery lingo, Haughom proudly admits to "taking things day by day." Can it be that simple? Yes.