Stress in the workplace is costing American business $300 billion a year.

That's the figure the American Psychological Association puts on the loss of productivity, absenteeism, turnover and increased medical costs caused by stress at work. According to a poll conducted by the association, two-thirds of American employees say work has a significant impact on their stress level, and one in four has called in sick as a result of stress.

Causes of stress, the association said, include job uncertainty, cost-cutting, a relentless demand for higher productivity and the proliferation of communications tools -- e-mail, cell phones, Blackberries -- that blur the boundaries between work and home.

Workers under stress are less efficient and less healthy than more contented employees, and that's bad for the bottom line, said Joseph Trunzo, an assistant professor of applied psychology at Bryant University.

Trunzo said stress is often a matter of perception. If workers believe their workload is too great -- whether it is or not -- they will develop symptoms of stress. Smart companies, he said, recognize the problem and take measures to fight stress.

The American Psychological Association (APA) has developed the Psychologically Healthy Workplace Awards program at the national and state levels to recognize companies that are taking measures to deal with employee stress.

"How can we help companies create a healthy environment and still meet their needs for productivity?" said Patricia Raymond, a psychologist at Eleanor Slater Hospital, and the Rhode Island Psychological Association's representative to the APA regarding the Psychologically Healthy Workplace Awards program.

Raymond said stress can result in "presentee-ism," in which an employee is physically present but mentally absent from the job.

Sometimes, it can be the small things that makes the difference. Trunzo said he knows of a company that arranges for a mechanic to pick up employee cars that need repair, fix them, and bring them back.

"Giving someone a raise doesn't necessarily alleviate stress, but a more flexible schedule, maybe allowing an employee to work at home, might work better," he said.