Many managers assume that when a worker takes a "duvet" or "mental health" day it is because they are simply being lazy or not committed to their job. But it may in fact be a warning signal that they are working too hard or in the midst of a family or relationship crisis.
A survey of more than 1,000 U.S workers by Chicago-based employee assistance programmes provider ComPsych has found that most workers who take an unplanned day off when they are not physically ill are doing so because they need to re-energise themselves and regroup mentally.
The other main reason for taking such days off was because workers were "responding to a crisis", said senior vice-president David Campbell.
Speaking to the Society for Human Resource Management's HR News, Campbell said: "We're running at 120 mph with work and family, and… you need to re-energize and re-focus. If you don't, you're going to get burnt out.
"They're doing something of pleasure. It may be going to a movie. It may be going for a massage. It may be doing absolutely nothing and sleeping until 9 o'clock. It's an excuse to kind of do nothing," he added.
Nearly a third of those polled cited family or relationship issues as the reason they would take a mental health day, with a fifth blaming work stress or workload.
Relationship problems were consistently among the top two reasons for calls to employee assistance programmes, the company added.
Taking mental health days could also be a result of workers being driven too hard by their managers or not being encouraged to use their full vacation entitlement, warned Campbell.
"If you take regularly scheduled time off… it's going to keep you sharp all the time. Take more than a day [at a time] take those vacations on a routine, regular basis," he said.
Employers needed to create a culture where it was acceptable and encouraged, from the top down, to take vacations and unplug from work.
Managers also needed actively to monitor that employees are taking all their time off and not accumulating large numbers of unused vacations days.
Other reasons for taking a mental health day included financial, legal and other personal issues, cited by 15 per cent, a "lack of energy" or well-being (12 per cent) and "boredom, no motivation", cited by five per cent.
It's not just a U.S issue, either. In February it emerged that a Japanese cosmetics company was giving employees up to three days off work for "heartbreak leave" and, also in Japan, last November six civil servants were hauled over the coals for spending their days diligently working on Wikipedia articles.