A man died from a heart attack after biting his nails until they bled.
John Gardener’s habit had become so severe the infection turned sceptic and caused a fatal heart attack just days after his 40th birthday.
He was rushed to hospital but died two weeks later.
His fingernail biting was so extreme that doctors believe he became immune to the pain.
An inquest heard he been treated for anxiety and depression in the years leading up to his death as his nail-biting habit intensified. He also suffered ill health as a result of being diabetic.
John’s GP Dr Daniel Vernon described Mr Gardener’s fingernails as ‘in constant poor condition’, causing him to lose almost all feeling and sensation in them.
And his mother Jean Gardener, 60, claimed more could have been done to stop her son's tragic death.
Speaking from her home in Wigan, Lancashire, the mum-of-three said: “It was such a tragedy, we’re all in shock.
“It’s really hit our family hard, there could’ve been more done to help him.
“I wouldn’t want this to happen to anyone else’s son - it’s just devastating."
Doctors believe John’s condition was able to deteriorate after he became immune to the pain he would’ve been suffering.
Dr Vernon said: “John’s nails were always in poor condition and they were often bleeding when he came to the doctors.”
The coroner at the hearing in Bolton heard how John underwent surgery to remove the tip of his finger eight days after being admitted into hospital.
Before that, he was treated with intravenous antibiotics and was monitored by medical staff daily to see if his condition improved as he said that he didn’t want to lose his finger.
He showed signs of slow but gradual improvement and didn’t display any signs of high temperature or fevers, the inquest heard.
Consultant hand and orthopaedic surgeon Chye Ng said he was as shocked by his patient’s sudden death as the family were.
He added: “The passing of John Gardener was really upsetting and shocking for all of the team.”
The court was told how in 2011 he also underwent an operation to amputate his lower right leg after he contracted leg ulcers - a not uncommon problem among diabetics.
A spokesman from Wrightington Wigan and Leigh Hospital Trust said: “We would like to extend our sincere sympathies to the family and friends of John Gardener.
“We always strive to provide safe, effective and compassionate care to all patients.
“It is clear from the evidence given at the inquest that John received a high standard of treatment throughout the time he was under our care.”
Recording a narrative verdict, coroner Alan Walsh said: “This is a death of great sadness to everybody - his death happened so suddenly.
“I believe John had a difficult life after being diagnosed with diabetes at just 10 months old and not only this, he had to come to terms with self-injecting himself twice a day.
“And then he had problems with leg ulcers and problems after surgery because of this.”