Billy Connolly was diagnosed with Parkinson's disease after a fan warned him his walk showed "distinct signs" of it.
The 71-year-old Scottish star confirmed he had been diagnosed with the illness last September, revealing he had also undergone surgery for prostate cancer.
Connolly has spoken about his health in detail, explaining it was a fan who encouraged him to seek medical help after watching him walking through a hotel lobby.
"It was the strangest thing of all. I was doing Conan O'Brien's thing and they put me up in the Sportsmen's Lodge in Los Angeles. I was walking through the lobby and every time I had gone through there was a crowd of boys and girls and a couple of adults," he recalled on a US radio show, according to MailOnline.
"It turned out they were dancers from Australia. The guy who was in charge of them came over to me one day and said, 'Billy, I'm a big fan, I'm from Tasmania.' He said, 'I'm a surgeon and I have been watching you walking, you have a strange gait'. That was the way he put it.