The health service must do more to tackle levels of staff illness, according to independent experts.
The interim NHS Health and Wellbeing report said by helping employees more trusts could improve performance.
Up to 15,000 staff absences a day could be saved if the NHS matched the improvement made by the private sector, the government-commissioned study said.
Unions agreed services were patchy, but also pointed out that NHS work was demanding and took its toll on staff.
The report said with more than 1m staff, the NHS should act as an exemplar for the rest of the economy.
It has cited examples of best practice from the private and public sectors, arguing the health service should be more proactive, particularly with physio and counselling services.
Annual NHS sickness levels of 10.7 days a year per employee are higher than the public sector average and 50% higher than the private sector at 6.4 days.
During the research, 11,000 staff completed questionnaires and 200 responses were received from NHS trusts.
Stress, musculoskeletal problems and mental health difficulties were the most common problems suffered.
Overall, eight in 10 said they thought health and wellbeing issues were affecting care.
Dr Steve Boorman, who led the review, said there was now a clear business case for the NHS to do more.
"Trusts that take health and wellbeing seriously perform consistently better on measures of quality, patient safety and efficiency."
The report was drawn up at the request of the Department of Health in England following the publication of a national workforce review last year.
That report by Dame Carol Black, the government's director for health and work, called for businesses to do more to tackle illness and promote healthy lifestyles.
It said ill-health was costing the economy £100bn a year.
Dr Boorman will now spend the next few months consulting NHS staff and government officials before drawing up a final report later this year.
Karen Jennings, head of health at Unison, said it had to be remembered that NHS work was demanding where staff were at risk of injury and infection.
She added that the "patchy occupational health system" must be tackled.
"That means managers taking a responsible approach to the health and wellbeing of their staff."
Sian Thomas, director at NHS Employers, agreed trusts needed to take the issue more seriously.
"As health is our core business we must put the health issues of our own staff at centre stage so that we all become role models for our communities."
And a Department of Health spokesman added that the report made a "strong case for change".
"Dr Boorman has identified many examples of best practice that we can all learn from and make a positive change for all NHS staff."