Nearly 650,000 UK workers call in sick each week, according to figures from the British Heart Foundation.
This equates to 2% of the workforce being absent through illness at some point every week, at an estimated cost to the UK economy of £100 billion per year.
The charity's research from its Health at Work programme found that the public administration and defence sector - which includes public sector roles - had the highest level of absence with around 51,000 people phoning in sick in a typical week.
This was three times the level reported in primary industries such as farming.
The study also found that many people's ill health limited their ability to do their job properly, even when they are able to make it into work.
Nearly half (44%) of respondents who reported a health problem lasting more than a year - which equates to eight million workers in the UK - said that they could not fully perform their work duties.
The figures also revealed that 16% of health problems among UK employees were related to heart and circulation conditions, while 6% were linked to diabetes.
The British Heart Foundation is calling on employers to do more to create well-being initiatives that could improve the health and productivity of their staff.
Lisa Purcell, project manager for the charity's Health at Work programme, said: "Sickness absence is a major concern for the health of our nation and costs businesses millions of pounds every year. But it doesn't have to be like this. The risk of numerous health conditions reported by workers, including coronary heart disease, can be significantly cut with improvements to their lifestyle.
"Businesses that have prioritised workplace health have been able to create a healthier, more productive workforce with fewer days lost to sickness."
