Way back in 1925, Wally Pipp experienced the most consequential headache in sports history. According to legend, the New York Yankees first baseman decided to sit out a game because his head hurt. Pipp was replaced by a rookie named Lou Gehrig, who would go on to a Hall of Fame career that saw him play 2,130 consecutive games at first base for the Yankees over 14 years. The Yankees traded Pipp to another team, and he soon found himself out of baseball. Over the decades, Pipp's name has become part of the sports lexicon: athletes often play through pain out of fear of getting "Wally Pipped"–losing their job to a backup because of injury.

Having to constantly look over your shoulder at the competition is not unique to the world of sports. Employees in various sectors are increasingly showing up to work sick or injured, partly from fear of getting "Wally Pipped".

The growing problem of presenteeism–being on the job but unable to perform optimally due to illness or injury–is garnering major interest from human-resources specialists and health professionals. "When you have presenteeism, there's decreased job performance and productivity loss," says Natasha Caverley, a human-resources specialist who studied presenteeism at the University of Victoria's school of public administration, in a phone interview from Victoria. "People aren't focused on the tasks that they're doing because of their illness or injury, and the quality and quantity of work suffers."

According to a 2004 study by the Cornell University Institute for Health and Productivity Studies, the most common ailments through presenteeism are colds and flu, allergies, asthma, arthritis, and migraines. Colds and flu are of particular concern because infected employees can spread them to colleagues, increasing the decline in productivity. Presenteeism can also extend to depression and other forms of mental illness that often go undetected since there may not be any visible symptoms.

The Cornell study, which was published in the Journal of Occupational and Environmental Medicine, found that presenteeism accounted for as much as 60 percent of the total cost of worker illness, exceeding the costs of absenteeism and medical and disability benefits. A study by American health researcher Walter Stewart quoted in the Harvard Business Review calculated that presenteeism costs American businesses more than US$150 billion per year in lost productivity.

Those numbers are likely similar in Canada. In a 2006 Decima Research poll, 79 percent of Canadians surveyed reported going to work sick at some point in the previous year. (This poll sampled 2,000 Canadian adults and is considered accurate within 2.2 percentage points.) Another report that same year by Desjardins Financial Security found that 62 percent continued to work while ill. The report stated that the leading reasons for working while sick were fear of lost wages and falling behind at work. (TDesjardins interviewed 1,501 Canadian adults, with a maximum margin of error of 2.6 percent.)

Those are hardly the only reasons for presenteeism. "Sometimes there's a work culture that says you just need to be here," says Paula Allen, vice-president of health solutions and product development for HR firm Shepell.fgi, in a phone call from her office in Toronto. "It's not a matter of the quality of your work; it's about showing up. Some employers inadvertently send that message because they focus very heavily on tracking absenteeism."

Says Caverley: "There's also the pressure that comes from a sense of professionalism. People think it's a sign of weakness to not come in to work, so they come in to demonstrate to their employer that they're committed to their work."

And then there is the fear that a sick worker may be deemed expendable and end up getting "Wally Pipped". In her study of public-service organizations, Caverley found that incidence of presenteeism increased when restructuring or downsizing was taking place. "They pushed themselves beyond their limits to participate at work because they didn't know what was going on," Caverley says.

Another reason for presenteeism is that employees often have an inflated sense of their value. They think that the office is unable to function without them. Conversely, they may also fear that time spent away from work may reveal that things run just fine without them and challenge their sense of worth to the company.

Not all fear-based presenteeism is unfounded. In fact, the road to presenteeism is often paved with good intentions. Caverley's study of public-service employees found that most public servants, despite their reputation as clock watchers, came to work sick because they felt a sincere need to serve their community. Workers in other industries also felt a strong connection to their colleagues and came in to work sick because they didn't want to let their coworkers down.

Caverley says that it's up to management to teach even the most well-meaning employees the cost of presenteeism–and to offer them options, such as working from home in order to have enough time to get back to full strength.

Dealing with presenteeism can pay major dividends. Says Caverley: "If you allow people to be human beings, then their level of engagement will increase and they'll think, 'This is a company I can stay with long-term.'"

Ultimately, the root of presenteeism can be chalked up to an organization's failure to take the long view. Managers and employees fail to see that working through illness to achieve immediate objectives may ultimately affect their long-term productivity.

Which brings us back to Wally Pipp. It seems that much of his story is actually urban legend. Pipp wasn't replaced by Gehrig because of a headache. In fact, Pipp was something of a workhorse, having played in more games for the Bronx Bombers between 1915 and 1924 than any other Yankee player. Ultimately, all those games wore him down, forcing the 32-year-old Pipp to make way for the younger Gehrig. Maybe Pipp's career would have lasted longer if he had just taken a few more days off.