Stressed out? IT professionals are an anxious crowd, says a new survey. But you probably didn't need a study to tell you that, right?

However, perhaps you didn't realize how stressed your colleagues actually are.

Two out of three IT managers say they're kept awake at night worrying about work, and 75% admit ongoing anxiety about application performance concerns, according to a recent online survey of 272 systems and applications managers conducted by TechWeb Network Research on behalf of OpTier, a provider of business transaction management software. InformationWeek.com is part of the TechWeb network.

Besides sleep problems, 25% of the responded reported suffering physical symptoms that they believe were the result of IT-related stress. Those symptoms include nausea, headaches, migraines, panic attacks, heart arrhythmia, and muscle twitches. And nightmares.

"IT people have jobs that have a lot of responsibility for a lot of reasons," says Terry Beehr, a Central Michigan University professor of psychology who researches stress issues. "If IT goes down, a lot of other departments can't do their work." There's a lot riding on the performance of IT, so professionals responsible for the technologies are often under pressure a great deal of the time. "IT is 24-by-7, plus that's combined with heavy workloads and work that needs to be done quickly," he says.

Also, IT is a job category that "spans boundaries," he says. That means techies "have demands and questions coming from a lot of different places," and many different people who "don't think like you," he says.

Indeed, the OpTier survey found that half of the IT managers reported receiving 20 E-mails or phone calls concerning a single service outage. And 18% said they've received more than 50 E-mails or calls about a single outage.

IT professionals' jobs are similar to that of many managers in that they carry responsibility for others. Airline pilots and air traffic controllers are another group having a great deal of responsibility for other people, Beehr says. However, pilots and air traffic controllers in their job performance have "extreme" responsibilities for others because of flight safety, he says.

As for the work burden of techies, "technology is supposed to make life easier, but for those who work with it, you can't slack off," he says.

The survey respondents reported that underlying causes of their job stress include the complexity of their companies' IT infrastructure and poorly defined goals.