A young man underwent a nine-hour operation to remove a brain tumour he had dismissed as a headache - and was wide awake the whole time.
Harry Cowling, 20, had the "surreal" surgery two weeks after being diagnosed with the cyst.
He had been suffering pins and needles that worsened into excruciating headaches, which he put down to a family history of migraines.
But when the pain became unbearable Harry booked an appointment at the opticians thinking his eyesight may be causing them.
An appointment in February revealed swelling on the back of Harry's optic nerves and he was whisked away to hospital.
Several scans later he was given the unimaginable news that he had a large tumour on the brain, EssexLive reports.
Just a fortnight later, he was lying awake having craniotomy to remove as much of the rare brain tumour as possible.
The pins and needles Harry was experiencing were actually "mini seizures", he would later discover.
Harry was offered the opportunity to go to University College London Hospital which specialises in neurology.
Doctors told him the operation was best done while awake, and he bravely agreed.
While the thought of being conscious for the surgery was daunting, Harry said he stayed in "survival mode" and quickly prepared himself.
On the day of the operation, Harry understood that it should last about four to five hours.
Reliving the "surreal" experience, he said: "I was just trying to be part of the team.
"Before the operation, the best thing I could do and to give myself the best chance of anything was to go there clear and calm."
Harry said he remembers hearing the noise of the shaver buzzing across the patch of his head they would operate on at the beginning and the numerous doctors moving around the operating theatre.
"I can't remember the start of it really, I remember going in there and I remember hearing the sound of the shaver shaving my head," he said.
"There was a doctor, the neurosurgeon who was doing most of the work and another doctor controlling the drugs so they could keep me as pain free as possible while keeping you awake.
"I had a guy that was moving my hands, touching my nose, touching his nose, crossing lines on paper to make sure the brain functions properly and the left side was still working.
"There was a doctor speaking to me, looking at movements, two doctors doing that and a few other people in room."
There were flashpoints of worrying pain where Harry says the top of his head "tensed up" but he pushed through.
"There were parts of it where I remember being in pain and tensing my hands and gritting my teeth," he said.
"I would really feel it and say I'm feeling pain. The best way to describe it is you know when you cut something and you chew down in your head and the top of your head tenses up - it felt like someone was cutting into that."
As the hours started to add up, Harry, of Essex, remembers becoming worried.
"It was supposed to be four hours long but ended up being nine to ten hours long," he added.
"Surreal is the best word, there was so much going on."
It was around the eighth hour when Harry lost all feeling in his left arm, leading him to fear he might never get it back.
But thankfully the loss of sensation was temporary and he woke up in the recovery unit later to hear the relieving news that most of the tumour was gone.
Harry expressed his gratitude towards the "amazing" doctors who treated him through the ordeal.
He is now undergoing chemotherapy which medics hope will get rid of the rest of the tumour.
In the meantime, friends and family have been keeping him going, including a group of pals who have set up a fundraiser to help rally support.
Seven of Harry's friends have committed to attempting The National Three Peaks Challenge, to raise money for The Brain Tumour Charity.
The challenge involves climbing the three highest peaks of England, Scotland and Wales in just 24 hours.
The fundraiser raised £15,000 in 24 hours and is now on more than £21,000.
