Across the UK there are more than two million people claiming incapacity benefit, costing the taxpayer in the region of £12.5bn a year.
The government believes 23% of those people are actually capable of work.
Burnley is one of two areas that has introduced a pilot scheme to reassess those on benefits to see what they are capable of doing.
Jo, 33, is a mother-of-two. She suffers from back and joint problems and has been claiming incapacity benefit for the past four years.
In January this year the Department for Work and Pensions (DWP) asked her to attend a medical to re-assess her ability to work.
About 1,700 people living in Burnley and Aberdeen - the other area to introduce the pilot scheme - have to attend re-assessment medicals.
How the test works
Prior to the medical test claimants have to fill in a form describing what they can and cannot do physically and mentally.
The test is then carried out by a medical professional, which does not necessarily mean a doctor.
Based on a points system, it covers mobility, speech, hearing and seeing as well as an ability to understand a task and concentration levels.
For example someone who cannot walk will automatically get 15 points.
A person who cannot sit comfortably for more than 30 minutes will score seven points.
If a potential claimant needs an alcoholic drink before midday everyday they will score two points.
If the claimant scores less than 15 points in total they will be deemed fit for work and be placed onto Job Seekers Allowance.
For some that could mean a drop in benefit of around £25 per week.
If more than 15 points is scored the claimant will continue to receive the benefit in full, although it is now changing its name to Employment and Support Allowance.
There is also a halfway house. If the interviewer finds the claimant capable of some work they will be directed towards a Pathways to Work Scheme and be supported as they go into part-time work.
The new assessments were introduced by Labour two years ago for new claimants and for people like Jo, who are reassessed about twice a year.
Jo scored just three points in her medical and was told she was fit for work. She said she was not happy with the way the medical was carried out.
She said: "I failed the medical and I think it was wrong.
"I don't think it was a fair examination. I didn't want him to completely examine me but just an examination of maybe lifting my legs or my arms, he would have seen what pain I was in."
Jo walks with her body tilted at an angle, she cannot carry her two-year old daughter or bathe her.
She appealed against the decision to withdraw her incapacity benefit and went to a tribunal last week. I met Jo as she came out of the hearing and she had won her case.
The person who assessed Jo at her original medical had written in his notes that she had "normal joints".
At the tribunal she was able to produce medical records showing she had been diagnosed with benign joint hyper-mobility syndrome. She believes that is why she was successful.