A Staffordshire Police detective claims catching Covid saved his life after what he thought was long Covid actually turned out to be a brain tumour.
Dad-of-four Dave Stubbs was astonished to discover he had been living with the tumour for nine to 15 years.
He was diagnosed with the growth after feeling what felt like an "explosion" in his head while he was self-isolating.
He is now facing two years of therapy to hopefully improve the life-changing effects the surgery has had on his brain.
The Stoke City season ticket holder, who has been a police officer for 22 years, tested positive for Covid-19 last June, after two of his colleagues caught the virus.
He said: "I had no symptoms but I was very paranoid about Covid because I have vulnerable family members, so I went for a test, and it was positive.
"Two days into self-isolation I had what I can only describe as an explosion in my head."
He adds: "It was like I was 50 metres underwater, the pressure was immense. I couldn't put my head down or rest as it was so bad.
"This continued for a number of weeks and at this point I decided to contact my GP as I was concerned I may have long Covid.
"At this point I had also lost strength in my right arm, I was unable to lift my arm up over my head and I was struggling to clench my fist."
Dave's GP sent him for an urgent CT scan and in July, he and his wife Rachel - who is also a Staffordshire Police officer - were given the devastating news that he had a large tumour at the rear of his brain.
It was too big for treatment and the only hope of saving his life was high-risk emergency surgery.
He said: "The thought of a brain tumour never even crossed my mind. My whole life was turned upside down. I had gone in a split second from a hard working guy with a whole future mapped out to realising that my life would never be the same again for me, or my family.
"I have three grown-up daughters and a son Elijah, who was nine at the time. We couldn't keep it from him and it was horrible having to tell him."
Dave, who was based at Hanley CID, underwent surgery at the Royal Stoke University Hospital in September.
Following the operation, he was told that the tumour had been slowly growing for between nine and 15 years and had become wrapped around the main vein in his brain, which meant surgeons had not been able to completely remove it.
"I was months, if not weeks, away from a fatal collapse.
"All the symptoms I had put down to the stress of my job were related to the tumour.
"I would have regular headaches, I gained a large amount of weight and had problems with my vision. I felt tired but still struggled to sleep.
"My personality changed as well. I became fixated on things like work. My blood pressure was also really high.
"Covid saved my life. I think it aggravated the tumour causing the bad headaches. If I hadn't have caught it I would have continued to ignore my symptoms."
The tumour has had serious consequences for Dave, but he says he feels lucky to still be here.
He said: "Later in the day I start to struggle with my words. I get a lot of brain fog and I struggle to read. I get absolutely exhausted, but I'm still alive so I can't complain.
"I've never suffered with my mental health before but now I suffer from anxiety and get agitated.
"It's frustrating that they couldn't get all the tumour out. I'm on 'watch and wait' - I'll have to go back for regular scans to monitor it.
"If I'm lucky it will stay dormant for a long time. If not I will have options for treatment."
Although he will not be able to return to front-line duties, Dave is hoping he will still be able to have a career with Staffordshire Police and - together with his family - has thrown himself into fundraising for brain tumour charities.
"The neurosurgery team at the Royal Stoke were amazing and saved my life," he said.
"I could not have got through the trauma of having the tumour without the wonderful support of three brain tumour charities, and brain tumour research receives just one per cent of cancer research funding.
"I want to raise money and raise awareness."
Dave's wife Rachel had her head shaved when he hit his initial £3,000 target, and Elijah - described by Dave as 'an absolute star' - has been fundraising at school.
He recently turned 10 and asked guests at his party to donate instead of buying him presents.
The three charities Dave is raising money for are Brain Tumour Support, The Brain Tumour Charity and Brain Tumour Research.