It's a cliché that anyone who's very neat, lives an ordered life or just likes to keep to a schedule is described as "a bit OCD".
But what is it really like to have an anxiety disorder that can take over your life?
"I'm a punish!" TV personality and Obsessive-Compulsive Disorder (OCD) sufferer Osher Günsberg, 47, admits.
He's among those taking part in this week's episode of the always fascinating You Can't Ask That, where questions about the condition are put to those who know first-hand.
"I'm so sorry – and I'm mostly saying sorry to my wife right now!" he adds.
With six other OCD-sufferers, Osher talks about life with OCD, explaining how they know what they're doing is irrational, but can't help it.
"I absolutely realised it was crazy and yet I couldn't stop it," he says of his compulsion to obsess over end-of-the-world climate-change catastrophes.
"I would have a compulsion to viscerally fantasise about catastrophes that had been predicted. It was as if the prism through which I view the world had been switched to doom."
Without treatment, help and hard work, however, it was just part of life. And for some it always will be.
So, is it just about being neat? Not even close, another sufferer explains.
"If someone is smiling and saying they have OCD because they have a clean house," he says, "you know straight away they don't have OCD."