Good weather, hangovers and romantic trysts motivated some staff to lie about absences, the study found.
Researchers have found that boredom and depression at work prompted almost two-thirds to call in sick because they are disillusioned with their jobs.
Some of the excuses reported were: "I fell out of the loft" and "I was beaten up by a bouncer". Pet problems were frequently cited with dog-related illnesses most common.
But, illness is the favoured excuse with four out of 10 absentees faking symptoms or using props such as crutches and make-up in preparation for a day off.
Half of all health-related excuses involve stomach upsets, which are hard to disprove, the study found.
Interestingly, workers between 18 and 34 years old are more prone to phoning in sick than their older colleagues, the `Daily Mail` reported.
The study, based on a survey of 2,000 firms, was conducted by accountants PricewaterhouseCoopers (PwC).
Nick Roden of PwC said coping with the pressures of family life was an important factor in many sick days.
He added: "For 21 per cent of workers, family responsibilities are the real reason behind sick days, perhaps highlighting the difficulties staff face achieving a work-life balance.