For three years, Heather Case had little time for anything but her job. During that period, Case, now 30, worked in public relations in New York City. She routinely put in 60- to 70-hour workweeks, not including the time she spent working at home or commuting 90 minutes each way from Westchester County, N.Y. "You had to work those kinds of hours to keep your clients and your boss happy," she recalls.

But Case was not happy. She felt fatigued, run-down and irritable. She lost touch with friends. She rarely had time for the five- to six-mile training runs she loved or to compete in 10k's and half-marathons. "In a nutshell, I was burned out and stressed to the max," she says.

About 40 percent of people who work report that their job is "very" or "extremely" stressful, according to the National Institute for Occupational Safety and Health in Washington, D.C. Workplace stress can cause or contribute to a variety of health problems, including headaches, insomnia, depression, high blood pressure, aching muscles, loss of appetite, exhaustion and irritability; and people who suffer from occupational stress (women are 60 percent more likely than men to suffer from it) miss four times more workdays than those with other occupational injuries and illnesses, according to the Bureau of Labor Statistics.

The primary cause of job stress is knowing that we have little control over what goes on in the workplace. No matter how hard we try, we can't have power over a mercurial economy, back-stabbing co-workers or temperamental managers. "People who feel they don't have control are the most stressed," says Barbara Reinhold, Ed.D., director of the Career Development Office at Smith College in Northampton, Mass., and author of Free to Succeed: Designing the Life You Want in the New Free Agent Economy (Plume, 2001).

When your job sends your stress levels soaring, your body reacts by unleashing torrents of stress hormones into your bloodstream, and your muscle tension, blood pressure and heart rate increase. This set of physical symptoms, known as the fight-or-flight reaction, won't cause much trouble if stress occurs only occasionally. However, if you're chronically stressed and your body is constantly in red-alert mode, your risk for a variety of diseases and ailments, including headaches, muscle pain and heart disease, goes up.

Are you so burned out by work that you're ready to pop a blood vessel just thinking about it? Here are tips on how to deal with the most common workplace stresses.

JOB STRESSOR NO. 1: Fear of Losing Your Job

Layoffs, a weak economy, an unpredictable stock market and corporate mergers are very real concerns and can mean pink slips for employees. "There's no permanent job security at all anymore," says Rosalind Chait Barnett, Ph.D., director of the Community, Families & Work Program at Brandeis University in Waltham, Mass.

What this can do to your body and spirit

Many women have a profound fear of failure, says Alice D. Domar, Ph.D., director of the Mind/Body Center for Women's Health at Boston IVF, and assistant professor of medicine at Harvard Medical School in Boston. And panic about losing your job can inflame this fear. It can dampen your self-esteem and sense of self-worth, and trigger anxiety (financial or otherwise) that may show itself in physical symptoms such as panic attacks, chest tightness or gastrointestinal problems.

How you can reduce this stress

- Make sure your boss knows your value. At pink-slip time, your manager will work hard to hold on to her best workers. But she won't fight for you if she doesn't know what you're contributing. "Most people make the assumption that their manager knows about everything that they are doing," says Marjorie Brody, M.A., a Philadelphia-based management consultant and author of Help! Was That a Career-Limiting Move? (Career Skills Press, 2001). But they often don't. Meet with your manager monthly and update her on your projects and accomplishments. If it's not possible to chat with your manager regularly, give her a written summary each month.

- Don't wait for a layoff to look for other opportunities. "Make a few networking calls," says Barbara Reinhold, Ed.D., director of Smith College's Career Development Office. Keep your resume updated, go on informational interviews, research companies you admire and have coffee with people who may be able to help you find another job. Then, if you are laid off, you won't have to start from scratch with a job hunt. Plus, you won't feel so "stuck" when you realize there are options out there.

- Even though it's hard to find a new job in a slow economy, look anyway. "If you have an attitude that there's nothing out there, then that's exactly what you're going to find," Brody says.

JOB STRESSOR NO. 2: Too Much Work, Too Little Time

Thanks to downsizing, the same amount of work is being distributed among fewer people. Technological advances like e-mail, voice mail, cellphones and laptop computers have made it possible to take our work anywhere. For many people, the only way to stay on top of the workload is to arrive early, stay late, work through lunch and on weekends, and bring work home.

What this can do to your body and spirit

Overwork can cause physiological damage such as insomnia (particularly if you drink a lot of coffee or cola), neck pain, headache and fatigue. It robs you of the time you might otherwise spend caring for your body with exercise and smart eating; plus, you don't have time or energy for emotionally nurturing pursuits such as relaxing with friends and family, performing community service, meditating and cultivating your spirituality. "When you spend all your time on work, your life gets seriously out of balance," says Harvard's Domar. "That's just not good for your mind or your body."

How you can reduce this stress

- Question your boss. "When your boss asks you to do something you don't have time for, you need to say, 'This is what I'm doing right now. Which is more important to you? Should I drop what I'm doing and do this, or should I continue doing what I'm doing?'" Brody says. "What happens is we just take it all on, we don't question, and then we get frustrated and stressed." Asking your manager which task you should be focusing on will also provide you with a sense of control over your workload.

- Write down everything you do for an entire week, then inspect your list for potential time robbers. E-mails, phone calls, going through the mail, interruptions from co-workers and meetings all can eat away at the time you need to perform the essential tasks of your job.

- Consult with others to work smarter. "One of the most useful things for reducing job stress is peer coaching," Reinhold says. Get together with two or three co-workers who understand your job, and brainstorm ways to streamline work processes and save time.

JOB STRESSOR NO. 3: A Work Environment That Makes You Feel Insecure (or Unsafe)

Distressing events in the news, such as workplace shootings and terrorism, as well as more common occurrences like sexual harassment, irate customers, back-stabbing co-workers and incompetent or temperamental managers all can make you feel vulnerable and powerless.

What this can do to your body and spirit

Fear about the safety of your work environment can cause increases in blood pressure, muscle tension and heart rate. Chronic fear and anxiety can lead to emotional ailments such as irritability, depression, anxiety attacks and even post-traumatic stress disorder.

How you can reduce this stress

- Evaluate your anxieties. Try to separate rational worries, such as concerns about an erratic boss, from fears about less-likely events such as bioterrorism. For example, if you work in customer service at a department store, facing irate members of the public is a more likely stressor than a terrorist attack. After you determine what worries are most grounded in reality, work with friends or a therapist to create strategies for coping with the situations most likely to occur.

- Don't isolate yourself. "There's a tremendous value in forming relationships at work," says Reinhold. "If you feel isolated and lonely, you're going to feel more afraid." Also, having friends at work helps when you need to talk over how to get that creepy guy from accounting to stop hitting on you or why your boss keeps snapping.

- Take action. If you are being oppressed by a co-worker, harassed (sexually or verbally) by a boss, or tormented by a client or customer, speak up! A human-resources or union representative can advise you on what to do, and taking action will give you a sense of control over the situation.

JOB STRESSOR NO. 4: Rigid Hours and Work Schedule

Having little or no flexibility in your work hours and schedule is very stressful, particularly to working mothers.

What this can do to your body and spirit

A lack of control can make you feel hopeless and pessimistic. "If you're stuck in a situation where you feel helpless to make it better, you're at a high risk for depression," Domar says. For working mothers who must work around the schedules of their employers, child-care providers, schools, kids' athletic events and musical recitals, etc., the lack of flexibility is especially taxing, physically and emotionally.

How you can reduce this stress

- Cultivate good work relationships. If you're on good terms with your manager and co-workers, you will be in a better position to negotiate change.

- Gather a group of like-minded co-workers and approach your manager to propose solutions. "Flexibility enhances productivity and profitability, and decreases the number of sick days for workers," Reinhold says. "Talk with your manager about how you can find ways to create a flexible program in your workplace."

- Be a star performer. "If you're a very good worker, you have a much better chance of being granted flexibility," Reinhold says.

"I revamped my life"

No matter how distressing your job is, you do have options, as Heather Case found. After realizing that by working excessively she was missing out on too much, she decided to make major changes. "I threw in the towel and revamped my entire life," Case says. She quit her public-relations position in New York City, landed a job as communications manager at The Culinary Institute of America in Hyde Park, N.Y., and bought a house five minutes from work.

She still puts in about 50 hours a week, but she has far more free time. "I have time to reconnect with the people who are important in my life, and to nurture the relationships with my friends that I had tossed aside for a few years." She also has time to exercise. Instead of squeezing in occasional two-mile runs, she has joined a competitive running club and now covers five or six miles four or five times a week. "I feel like a different person," Case says. "I have a whole new perspective now."