It found almost half a million people have had to leave work for medical reasons within five years before they were due to retire.
In March the government announced an independent review into the state pension age.
Research by the TUC research points to a significant north/south divide.
In the south west of England, just one in 13 people blamed sickness or disability for leaving work. However, that figure rises to one in seven in the north of England, Scotland and Wales and one in four in Northern Ireland.
Those in the lowest-paid jobs or in manual work are also twice as likely to stop working for health reasons than managers or professionals.
TUC general secretary Frances O'Grady said: "These figures show that we must hold off on any further rises in the pension age until we have worked out how to support the one in eight workers who are too ill to work before they even get to state pension age.
"People should be able to retire in dignity with a decent pension when the time is right. Older workers have a crucial role to play in the labour market but we can't expect the sick to wait longer to get a pension when they may need financial support more than ever."
A government review of the state pension age is being led by ex-CBI chief John Cridland. Its findings are due to be published in May.
The state pension age is set to rise to 65 for both men and women by November 2018 and 67 by 2028.
Tom McPhail, head of retirement policy at financial services firm Hargreaves Lansdown, said earlier this year: "Those joining the workforce today are likely to find themselves waiting until their mid-seventies to get a pay-out from the state system."

The dinosaurs were able to make the journey when a spell of warming allowed passage over frozen land bridges between the continents.
Two fossil discoveries in Australia shed new light on this theory.
Both specimens are sauropods - a group of large, herbivorous dinosaurs with long necks and small heads.
Further classified as titanosaurs, they are among the largest dinosaurs ever to walk the Earth.
Lead researcher Dr Stephen Poropot, of the Australian Age of Dinosaurs Museum, said the specimens add to our knowledge of the area 95 to 98 million years ago.
"We get a much better idea of the overall fauna," he said.
"And as a result we can start piecing together how climate affected these dinosaurs, how the positions of the continent affected those dinosaurs and how they evolved through time as well."
One of the dinosaurs was found near the town of Winton in Central West Queensland.
It has been named Savannasaurus elliottorum after members of the Elliott family, who found the fossil in a pile of bones while rounding up sheep at their property.
The skeleton has been pieced together from 17 pallets of bones encased in rock - a process that took 10 years.
The researchers also uncovered head bones from another sauropod species Diamantinasaurus matildae.
"This new Diamantinasaurus specimen has helped to fill several gaps in our knowledge of this dinosaur's skeletal anatomy," said Dr Poropat.
"The braincase in particular has allowed us to refine Diamantinasaurus' position on the sauropod family tree."
The two specimens have helped to show that titanosaurs were living worldwide by 100 million years ago.
This became possible because of the arrangement of the continents and changes in the global climate.
Prof Paul Upchurch, of University College, London, said Australia and South America were connected to Antarctica throughout much of the Cretaceous.
When Savannasaurus was alive, 95 million years ago, global average temperatures were warmer than they are now, but it was quite cool at the poles.
"We suspect that the ancestor of Savannasaurus was from South America, but that it could not and did not enter Australia until approximately 105 million years ago," he said.
"At this time global average temperatures increased allowing sauropods to traverse landmasses at polar latitudes."
The research is published in N Scientific Reports.
Follow Helen on Twitter @hbriggs.

Two crews and a hovercraft from Weston-super-Mare were called just after midnight to rescue two adults and the children from Uphill beach.
The police and ambulance service also attended, the fire service said.
Avon Fire and Rescue have warned people not to park or walk on the beach in the dark due to the fast-rising tides.
Ill-health or disability is forcing one in eight people to stop working before they reach the state pension age, the TUC says.
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Some of the giants of the dinosaur family may have originated in South America and crossed over Antarctica to Australia about 100 million years ago.
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A family of five, including three young children, had to be rescued from a Somerset beach after their car got stuck in the mud on Saturday evening.