Sickness absence totalled 137 million working days last year, the equivalent of 4.3 days per worker, the Office for National Statistics (ONS) said.
When records began in 1993, the equivalent of 7.2 days were lost.
Minor illnesses such as coughs and colds accounted for a quarter of days lost last year, the ONS said.
TUC general secretary Frances O'Grady said: "It is a myth that UK workers are always throwing sickies.
"We are really a nation of mucus troopers, with people more likely to go to work when ill than stay at home when well.
"Sickness absence rates have fallen steadily over the past decade, and let us not forget that working people put in billions of pounds worth of unpaid overtime each year."
Back and neck pain were high on the list of causes of sickness absence, as were mental health issues including stress, depression and anxiety.
Sickness absence rates were highest in Wales and Scotland, at 2.6% and 2.5% respectively, and lowest in London, at 1.4%.
Other findings for last year included:
ONS statistician Brendan Freeman said: "Since 2003, there has been a fairly steady decline in the number of working days lost to sickness, especially during the economic downturn.
"In recent years, there has been a small rise in the number of days lost, but due to an increasing number of people entering the workforce, the rate per worker and overall sickness absence rate have stayed largely flat."
Sir Cary Cooper, professor of organisational psychology and health at the Manchester Business School at Manchester University, said that people were frightened of taking time off for sickness, and that presenteeism was a big threat to UK workplace productivity.
Just over four days were lost to sickness per UK worker last year - the lowest since records began, official figures show.