People in the UK spent a record £1.1billion on private healthcare last year in an attempts to avoid NHS waiting times.
Excluding cosmetic surgery, the amount spent on private treatments rose 75 per cent to £793milllion between 2012 and 2017.
Knee and hip operations, cataract surgery and cancer treatment are the three most commonly paid-for therapies.
Experts warn longer waits for free healthcare are 'without doubt' driving people to fork out, with some parts of the NHS keeping people waiting until their conditions become constantly painful or crippling.
And patients' rights campaigners say people who can't afford surgery's hefty price tags have 'no choice but to suffer when the NHS lets them down'.
An analysis by market intelligence company Laingbuisson revealed some NHS hospitals are even making a profit because of income from their private units.
Many people are paying one-off costs for treatment when they need it, with no big change in the number of people paying for private insurance, The Times reported.
There are more than four million people on waiting lists for NHS treatment in England and national waiting time targets haven't been met for at le'Lengthening waiting lists without doubt are driving it,' said Laingbuisson chairman Keith Pollard.
'It’s the big routine stuff – hips, knees, cataract operations, hernia operations – that isn’t seen as urgent.'ast two years.
The £1.1billion figure is the first time the spending has passed into 10 figures, and the amount people are paying themselves has risen 50 per cent in five years.
Private revenue for NHS hospitals has risen to £620million, up around 20 per cent in the same time period, the analysis said.
Surgery rationing done by the health service is partly to blame, experts said.
Patients paying for the most common procedures – cataract surgery or knee or hip replacements – can be denied an op by the NHS until they can't see or are living in constant pain.
The average hip replacement costs £11,468 at a private hospital, with the price as high as £15,050 in some places.
And cataract surgery costs £2,464 on average, rising to as high as £3,535.
The entire private healthcare sector is worth £5.8billion, 20 per cent more than it was in 2012.
