Ant McPartlin reportedly turned into a "recluse" after he became dependent on painkillers.
The "Britain's Got Talent" host checked into rehab over the weekend in order to beat his drug and alcohol addiction but, although he's only just admitted to having a problem, his friends started to see the warning signs months ago when he refused to leave the house.
A source told The Sun newspaper: "Ant simply wasn't leaving the house unless it was for absolutely necessary work like "BGT" or the BAFTAs of medical treatment on his knee.
"He'd become a virtual recluse stuck in the house because of the total agony he was in, becoming dependent on medication over months and months.
"In the last few weeks it got worse and he wouldn't even leave the house to go to the shops."
The 41-year-old TV host will reportedly now spend at least two months in the clinic trying beat his demons while his wife Lisa and his on-screen partner Declan Donnelly support him from afar.
And they're not the only ones who are determined to help Ant through this period as ITV - who work with the star on numerous projects and shows - have admitted he has their "total backing."
A senior executive said: "The feeling among senior executives us that Ant has been very brave to admit this. He's got our total backing and he knows he can take as much times as he needs. If there's anything we can do to support him in getting better, then of course he only needs to ask. He's a huge part of the ITV family and that isn't going to change.
"He has many friends here who are right behind him and we hope to see him out of rehab and on the mend as soon as possible."
The "I'm A Celebrity... Get Me Out of Here!" host believes things started to spiral out of control two years ago when he had an operation to fix cartilage in his right knee.
In a bid to numb the pain, Ant began taking the prescription drug Tramadol and soon realised that he'd become hooked on the painkiller, which can cause speech disturbances, lack of co-ordination, headaches and drowsiness.
A source previously said: "Ant liked nothing better than a round of golf to unwind - but now he has been told he may never play again.
"You've never seen him so down. He's been trapped in his house causing him to turn to substance abuse as a way of escaping his troubles."