Amy WinehouseAmy Winehouse has been in hospital for the past week.

But what's ailing the star?

Amy's dad, Mitch, has opened up on the details.

In a frank interview with the Sunday Mirror, Mitch, who drove Amy to a London clinic after she fainted last week, has revealed that his daughter is suffering from chronic lung condition emphysema.

"She's got emphysema," he said.

"It's early stages, but had it gone on for another month they (the doctors) painted a very vivid picture of her sitting there like an old person with a mask on her face struggling to breathe.

"With smoking the crack cocaine and the cigarettes, her lungs are all gunked up," he continued.

"There are nodules around her chest and dark marks.She's got 70% lung capacity."Amy with dad Mitch

Mitch went onto say that Amy now has to start cleaning up her act, otherwise the disease may prove fatal.

"The doctors have told her if she goes back to smoking drugs it won't just ruin her voice, it will kill her.

"I'm saying to those drug dealers, and they know who they are, if they are supplying crack to Amy, then they've got to take responsibility.

"I don't want her hanging out with her mates like Pete Doherty either," he added.

Mitch also said that despite the fact that Amy is expected to stay in hospital for the next few days, doctors have said there's no reason why she won't be able to perform at Glastonbury next weekend.