Thirty-two percent of workers say they have called in sick when they felt well at least once in the last year, according to a survey by CareerBuilder.com. One-in-ten workers admitted to doing so three times or more.

While some employers said they typically don't question excuses given, others were more skeptical. Twenty-seven percent of hiring managers reported they have fired a worker for calling in sick without a legitimate reason.

The online survey included 1,650 workers and 1,150 hiring managers nationwide.

The most popular motivator for missing work was the need to relax, according to nearly half (48 percent) of workers. Twenty-four percent of workers pointed to the desire to catch up on sleep while 20 percent cited personal errands. Other top reasons included doctor's appointments (17 percent), plans with family and friends (16 percent), and housework (16 percent).

One-in-four workers said they consider their sick days to be equivalent to vacation days and treat them as such.

"Although an improvement from last year, the amount of unexcused absences from the office is significant and can be indicative of employee dissatisfaction," says Rosemary Haefner, vice president of HR at CareerBuilder.com. "Forty-five percent of hiring managers have caught an employee calling in sick with a fake excuse. This begs two questions: Do you have the right employees working for your organization and do you have the right employee management practices in place for your staff?"