Daniel Radcliffe has to have regular checks on his heart

He said: "You have to be on blood pressure medication and have an ECG every so often ... but don't worry, I'm perfectly fine."

The 25-year-old star was also left unimpressed when visiting the US embassy for a visa interview, only to be told by a member of staff he looked "tired".

He told The Guardian newspaper: "I was like, er, thanks random person who works at the embassy."

Daniel shot to fame playing the lead role in the 'Harry Potter' franchise and he admits he has always put himself under pressure to do well as he feared his career would be over when the film series came to an end.

He said: "I think I have to apply that amount of pressure to myself because I want to do well. Now, maybe that's not the healthiest way to function ... but also, frankly, since the age of 20, all of the interviews I've done have involved people asking about my impending failure, and how I felt about the possibility of that.

"And so, when you're confronted with that so often, you start to react to it. My own reaction was always to kick hard against it and think, f**k it, you might as well be bold now, make some interesting choices and see where that takes you."