The burden of staff illness in Westcountry hospitals has cost them over £79 million in sick pay in the last five years.
Over that period, a minimum of 142,000 days have been lost to staff forced to take time off with musculoskeletal injuries, such as backache.
Unions say not enough is being done to support staff.
"This figure is not a surprise at all," said Sue Matthews, regional officer for the Royal College of Nursing. "People are made to feel guilty about taking time off, so you get people going to work when ill.
"For nurses the worry is that if they're not 100 per cent and they make a mistake it affects the patients and their career."
Suzy Franklin, branch officer for Unison at Plymouth's Derriford Hospital, said staff were reluctant to call in sick.
"People do come in with flu- like symptoms. It is putting people's health at risk."
According to figures obtained under the Freedom of Information Act, Derriford Hospital paid out £23.7 million in sick pay over four years, with over 24,000 full-time equivalent days lost to people suffering from musculoskeletal conditions – one of the top two reasons for absenteeism in the NHS.
At the Royal Cornwall Hospital Trust (RCHT) in Truro, just over £22 million in sick pay was paid in under five years, with 27,000 days off taken because of musculoskeletal conditions.
The Royal Devon and Exeter Hospital (RDE) sick pay costs in the four-and-a-half years to October 2012 were at the £16 million mark, although it clocked up 50,000 days off due to musculoskeletal problems.
At South Devon Healthcare, which runs Torbay Hospital, there were costs of around £13 million in sick pay over the four years to October 2012. This covered over 29,000 days off sick.
Since April 2011, Northern Devon Healthcare, which runs the main hospital in Barnstaple and 17 community hospitals, paid just under £6 million in sick pay and there were 12,600 days off due to musculoskeletal conditions.
The Chartered Society of Physiotherapists say too many hospital trusts are wasting money on sick pay which could be better spent on patient care. Hospital trusts say they are working to reduce staff absence and that sickness absence accounts for a tiny proportion of total work days "available".
Derriford Hospital has more than 6,000 staff, who cumulatively work nearly 2 million days in a year. A spokesman for the Plymouth-based trust said the current time lost for all illness is 4.49% and a sickness absence manager had recently been appointed to focus on bringing this down.
Nick Macklin, director of human resources and organisational development at RCHT, said they had recently enlisted the expertise of the European Centre for the Environment and Human Health to help improve health and wellbeing among staff.
"We have a clear action plan that is designed to both prevent staff sickness and help people come back to work as quickly as possible," he said.
Northern Devon Healthcare Trust said it had a dedicated back care team to help staff and was working to reduce this burden.
At South Devon Healthcare, the overall attendance rate for 2012/13 was 95.96%.
A spokesman added: "The trust puts a high priority on staff morale and staff values and culture."
An RDE spokesman said its sickness rate was 3.88% and work was ongoing to reduce that.
