Chronic fatigue syndrome, or ME, is incorrectly treated, lacks sufficient funding and is poorly understood by many in the medical profession - according to an MP who has been campaigning in Parliament to change attitudes.
During an emotional Westminster Hall debate, Scottish National Party MP Carol Monaghan argued that graded exercise therapy (GET) - offered most commonly on the NHS - is often damaging and in need of serious revision.
But researchers behind a trial of the therapy say it is a safe method of treatment.
Guidelines on how the illness should be treated in England are currently being updated.
In the debate, Ms Monaghan said: "Characterised as 'yuppie flu', and misunderstood by doctors and politicians alike, we need properly-funded biomedical research into the causes and treatment of those with ME.
"Less than £1 is spent annually on each ME patient in the UK."
GET involves patients doing increasing amounts of exercise, over weeks and months, depending on their individual needs to aid their recovery.
But MPs cited stories from constituents suffering with ME who say that GET has made their illness worse.
Ellie Bunce, 21, was diagnosed with ME in 2016 and it has forced her to put her sporting ambitions on hold.
"At the time I was 19, a student athlete - in my second year of university - with hopes of rowing internationally. I was fit, active, I ate well, I exercised.
"I was happy and positive and yet one day I woke feeling as if I was dying. My whole body ached in a way I'd never felt before."
Ellie says the first specialist she saw suggested her lifestyle was to blame.
"He said I should make more effort to wake up at 09:00, get showered, dressed and then go on a long walk. This was my 'treatment plan'.
"However, the more I pushed myself to get out of bed, the more ill I got."
After several months, Ellie was eventually diagnosed with ME.
"Day-to-day every inch of my body is in pain, I struggle to read and concentrate, I'm too tired to move.
"I spend upwards of 20 hours in bed a day. I've been stripped of my hobbies, energy and work.
"I live in the hope that one day doctors will find a treatment and that one day I will be better."
The health watchdog, NICE, is currently updating its guidelines for treatment in England, but publication is not due until 2020.
At the debate, Liberal Democrat MP Ed Davey called for GET to be suspended before the NICE guidelines are reviewed, raising the possibility that there could be future lawsuits from ME patients whose condition has worsened from the treatment.
In 2012, the ME Association conducted a survey of almost 1,428 patients diagnosed with the condition.
It found that of those who were prescribed GET, the symptoms of 12% improved, 14% were unaffected and 74% suffered worse symptoms.
However, other health experts argue that GET is a proven and safe method of treatment.
In 2011 a large-scale trial, known as the PACE trial, considered treatments including GET and Cognitive Behavioural Therapy (CBT).
Prof Michael Sharpe, one of the study's lead researchers, said: "The trial found that GET can be moderately helpful in reducing fatigue and disability. We also found that it didn't cause harm.
"So the question is why is there a contradiction between the trials and what people are saying? Well it could be because diagnosis is a bit hit and miss, it could be that GET hasn't been done in a careful way.
"More research is needed to find out why there is such a difference."
A NICE spokesman said: "We do recognise the controversy about the currently-recommended treatments and will discuss with the expert committee, once appointed, before deciding on any action prior to the completion of the new guideline."
There was an emotional outpouring of support on social media during the debate from sufferers, many of whom feel marginalised and forgotten, with no cure for their illness in sight.
A tweet from Emma, who said the illness had robbed her of her 20s, was typical:
What is ME?
- Myalgic encephalomyelitis or ME is also known as Chronic Fatigue Syndrome (CFS)
- The long-term illness affects around 250,000 people in the UK
- As well as fatigue, it can cause sleep problems and muscle and joint pain
- Living with CFS/ME can be difficult. Extreme tiredness and other physical symptoms can make it hard to carry out everyday activities
- There is currently no cure for ME
Charities also welcomed the debate in Parliament and John Siddle of the ME Association said: "We are extremely grateful to Carol Monaghan for securing the debate - but in truth, the hard work starts now.
"Many doctors still don't know how to diagnose and manage ME, and lack of research means that we still don't have any effective forms of treatment.
"This is a completely unacceptable situation for a disease which affects 250,000 people and their families."