More than half (53%) of respondents state that they feel too guilty to take time off when they are genuinely ill, according to research by online job site CV Library.
Its survey of 1,100 employees also found that 51% of respondents do not want to take time off when they are unwell because they do not want to let their team down, while 14% feel that their boss is not very understanding if they are ill.
Lee Biggins (pictured), founder and chief executive officer at CV Library, said: "There seems to be a stigma around taking sick days, with many fearing that their manager won't believe them or they'll get too behind on their workload.
"Another problem that often arises is sick pay, with those who go unpaid being even less likely to take the day off, despite being unwell."
Around a quarter (24%) do not like taking sick days because they believe it reflects badly on them, and 13% think that calling in sick is frowned upon at their place of work.
Nearly three-quarters (74%) of respondents only take one or two days of sick a year, with only 18% of employees surveyed claiming they have taken a sick day in the last 12 months.
Biggins added: "As an employer, it's important to make sure [there is] a policy in place that encourages staff to take time off when they're ill, whether this is a physical or mental ailment.
"When employees come into work feeling sick, they're less productive and more likely to pass on their illness to other members of the team. As such, it's better for both parties that they take the time out to recover."
