A mum was left devastated when her fun-loving daughter died aged just 21 - of an illness some medics don't think exists.

Merryn Crofts was confined to her bed for the last three years of her life and died last May, weighing less than six stone.

Now her mum Clare has spoken of her anguish in a bid to increase understanding of ME.

Merryn had severe myalgic encephalomyelitis - or ME - a neurological illness which affects up to 17 million people worldwide, according to some estimates.

But many think the condition is not real, even within the medical profession.

ME sufferer Merryn Crofts

Clare, of Norden in Rochdale, told the Manchester Evening News : “Merryn was passionate about raising awareness and understanding of ME.

“She wouldn’t want other families to suffer like we have.

“But she was also ashamed of having ME. Quite often, if asked, she would say she had a neuro-immune disease.

“That’s because there is a still a stigma around ME, even in the medical community, and there is a lot of misinformation about ME out there. That has to change.”

ME sufferer Merryn Crofts

The first sign something was wrong came when Merryn, then aged 15, suddenly developed severe swelling around her face, hands and feet.

Doctors thought the Oulder Hill High School pupil might have an infection and prescribed antibiotics, but the symptoms worsened.

Then, the drama-mad schoolgirl began experiencing severe fatigue, a telltale sign of ME.

ME sufferer Merryn Crofts

Clare, who quit her job as a counsellor to become Merryn’s full-time carer, said: “From being very young she was always a bundle of energy. She was a daredevil, always doing stuff.

“But she would come home from school, crash on the sofa and sleep for six hours.

“It was like watching a wind up toy run out of power.

“And it just kept happening more and more.”

As her symptoms worsened Merryn underwent several mental health assessments as doctors thought the illness might be psychological, a common misdiagnosis among ME sufferers.

Conversion Disorder, a mental condition formerly known as hysteria, was even mentioned.

ME sufferer Merryn Crofts

However, through her own research Clare began to suspect Merryn might have ME, a possibility she admits ‘scared me to death’.

But, despite repeatedly raising her concerns with doctors, she was met with a wall of suspicion.

“One doctor told us if they could discount everything else, then maybe they would diagnose ME,” said Clare.

“Another just said he didn’t believe in it and that was that.”

Her experience was not uncommon.

ME has always sparked debate and controversy.

It’s been disparagingly called ‘yuppie flu’, because one of its many symptoms is severe, persistent fatigue after exercise.

Merryn (right) is pictured with mum Clare (second left), sister Amy and step-dad Dave Norton

And, while its cause is unknown, many patients contract it after a viral infection - Merryn had suffered a bout of glandular fever before her symptoms began - and women are four times as likely to have ME than men.

Frustrated with the lack of progress in the NHS, Merryn went to see a specialist at a private clinic and was diagnosed with severe ME.

Then in September 2012, an NHS ME consultant in Wigan also agreed Merryn was suffering with the condition.

Clare said: “It was always a battle. ME is recognised by the World Health Organisation as a neurological disease - and has been since the 1960s - there are NICE guidelines on it, but still doctors were telling us they didn’t believe in it. It was like banging your head on a brick wall.”

By now, Merryn was enduring a string of agonising symptoms.

Wheelchair-bound and unable to climb the stairs at the family home she also shared with older sister Amy, now 24, and step-dad Dave Norton, she developed an excruciating sensitivity to light, noise and touch, suffered crippling stomach cramps and joint pain and began having convulsions.

In a heartbreaking blog post from August 2015, Merryn gave an insight into what she was going through.

ME sufferer Merryn Crofts, of Norden, Rochdale

“Having severe ME is like being trapped in your own body every single day,” she wrote.

“There is no rest, you are bed-bound all day every day.

“It snatches the most simple things away from you like being able to wash yourself, even in bed. Being cared for in every way possible. In terrible pain, from everything. Not being able to talk on the phone or have visitors, and feeling worse about saying no every time someone asks again.

“Months and months in hospital. Severe infections. Breathing problems. Low immunity. Problems anywhere and everywhere in the body. Paralysis. Severe hypersensitivity. The list is endless, and if I was physically able to type I would carry on.

“Spread awareness and remember all of us and all of those who have lost their lives.”

Watching her daughter go through such torment was also agonising for Clare.

“Merryn’s pain was always very bad,” she said.

ME sufferer Merryn Crofts

“She was always a really ‘huggy’ girl, but she couldn’t be touched because it was agony for her.

“We kept thinking it can’t get any worse than this, but it always did.

“We were constantly weighing up how much energy she had in reserve, how much she could cope with. It got to the point where she had nothing in reserve, she was always borrowing from the next day, always deteriorating.

“Going into hospital was torture for her. Every time she went in she would always come out worse. ME is a constant battle, you never get the chance to recover. There is never any respite, it never ends.”

As the ME began to attack the muscles in her throat Merryn also began to have problems eating.

And her stomach problems meant what little food she could digest was often vomited back up.

Her weight began to plummet - she was 5ft 7ins tall, but less than 6st - so tube feeding became her only option.

ME sufferer Merryn Crofts

At the same time she was on ‘massive’ doses of ketamine and morphine to help her cope with her pain, sometimes receiving hourly injections.

Then, in spring 2017, Merryn was diagnosed with an infection.

It meant she had to stop using her feeding tube.

She was given the option of going into hospital to receive a huge dose of antibiotics, of which there was no guarantee of success, followed by a long ‘refeeding’ process, or staying at home.

Clare said: “Merryn said she wasn’t going back into hospital. She knew what the consequences were. She lasted three months. It was absolutely torture.”

On the night she died Merryn called her mum into her room.

“She asked if I could call out the district nurse, then she said to me ‘I’ve got to be getting off now mum’,” said Clare.

ME sufferer Merryn Crofts

“I went downstairs to wait for the nurse. When we went back she was gone.

“Looking back it was like she was telling me in such a nice way. It’s like her last thought was how can I make this easy for my mum.”

Merryn wrote letters to her family to open after her death.

They took her a year to complete as just typing out a few letters at a time left her exhausted.

During her darkest days shopping-mad Merryn loved to order clothes online, especially Ted Baker outfits, even though she couldn’t wear them and after opening them would leave them in their original packaging with the labels still attached.

After her death her family held a sale, which they dubbed ‘Merryn’s Pop-up Boutique’, which raised £1,200 for the Grenfell Tower appeal.

Merryn’s brain and spinal column was also donated to the Ramsay Research Fund - a charity investigating the causes of ME.

In May an inquest into Merryn’s death is due to be held.

ME sufferer Merryn Crofts

Her family hope it will find she died from ME.

If that happens she would become only the second person in the UK to have the illness as their official cause of death, after 32-year-old Sophia Mirza, who died in 2005.

“It would mean so much to Merryn and so much to the ME community to have ME acknowledged as the cause of her death,” said Clare.

“There is still so much we don’t know about the disease. We have to start properly funding research into it and acknowledging it can kill.”

The ME Association campaigns to improve access to care, treatment and research and remove the disease’s stigma.

ME Association honorary medical adviser Charles Shepherd said it was ‘essential’ Merryn’s ‘untimely death is not overlooked’.

He added: “There are many people, even within the medical profession, who continue to think ME is all in the mind. It’s about time we put this myth to bed once and for all.

“It is essential that Merryn’s untimely death is not overlooked and the urgent need for proper recognition of, and research into, ME is recognised.

“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.

“In our present state of knowledge, we don’t know if ME can kill directly, but there are various consequences of having the illness that can increase the risk of early death.

“How many more people have to suffer before ME merits properly funded biomedical research?”

For more information on ME, visit meassociation.org.uk.