But a determined nurse was keen to make one final attempt to get to the bottom of his problem and made an amazing discovery – a tooth jammed in Mr Hirst's ear canal.
His earache and infections had left doctors baffled and him partially deaf. Now the 47-year-old is enjoying unhindered sleep for the first time in decades and his intense piercing headaches have disappeared.
It's still a mystery, however, as to how the tooth ended up stuck in his ear.
He first complained of pain in his right ear as a teenager, and since then has attended countless hospital appointments in an attempt to discover the bizarre cause of his mystery condition.
"I've been plagued by earache since he was around 14," said Mr Hirst. "The pain wouldn't go away and I couldn't concentrate because it was always there.
"I used to use a lot of cotton wool and cotton buds and was prescribed antibiotics because I was always getting infections. When I was younger I used to just sit and bang my head on the wall because it hurt that much.
"I would be screaming in pain, that's not exaggerating. It was a sharp jabbing pain and it just wouldn't go away. I've lost count of the times I have been examined but no one spotted the tooth.
"I went again and again to the ear, nose and throat clinic. I don't know why but they never came across the tooth. I decided to have one last try to sort it out and I booked an appointment at the Royal Hallamshire Sheffield."
There, a persistent nurse used a suction tube in his ear to clean it thoroughly and tried to see what might be causing his pain with a microscopic probe.
Mr Hirst said she then used tweezers to try and pull out an obstruction but was struck silent in astonishment at what emerged.
"She didn't say anything at first, she just stood there looking amazed," he added. "Then she said to me: 'Have you lost any teeth lately?' I said I'd not had any teeth in my head for years.
"The nurse said she couldn't believe what she had found in my ear and showed me the tooth. She said in 20 years she's never seen anything like it.
"I would think it's a first tooth, looking at it, because it can't be big enough to be an adult tooth. I think it's a bottom tooth, one of the front incisors."
Mr Hirst, from Shiregreen, Sheffield, who has two children, Rebecca, 20 and Kai, nine, had to give up work as a miner 15 years ago partly due to his ear condition.
He has a number of theories as to how the tooth could have lodged itself in his ear canal.
"At school we had wooden desks with lids, and one day I was swinging between two of them," he said. "I fell between them and smashed the back of my ear, it might have happened then.
"Once I also fell and broke my two front teeth, or it could be that I pushed it in when I was a kid or something. I'm still puzzled as to how it got there. They gave me the tooth and I'm keeping as a souvenir.
"I can hardly hear anything in my right ear, the eardrum has disintegrated but the main thing is the earache has now cleared up completely.
"It's absolutely brilliant. Why the tooth wasn't spotted all those years ago I will never know but I'm just grateful to the hospital staff for finding the tooth now, better late than never."