Bradley Cooper was once so wasted he purposely banged his head on a concrete floor.

The 'Hangover' actor used to regularly drink alcohol and take DRUGS but realised he had a problem when he deliberately harmed himself just to show people he was ''tough''.

He told the Hollywood Reporter: ''I was at a party, and deliberately bashed my head on the concrete floor. Like, 'Hey, look how tough I am!'

''I did it again. And I spent the night at St. Vincent's Hospital with a sock of ice, waiting for them to stitch me up.''

Following those incidents, Bradley decided to completely quit DRUGS and alcohol eight years ago and says it was a turning point for him.

He added: ''I don't drink or do DRUGS anymore. Being sober helps a great deal... I remember looking at my life, my apartment, my dogs [when I was still using], and I thought, 'What's happening?'

''I was so concerned what you thought of me, how I how I was coming across, how I would survive the day.

''I always felt like an outsider. I just lived in my head. I realised I wasn't going to live up to my potential, and that scared the hell out of me. I thought, 'Wow, I'm actually gonna ruin my life. I'm really gonna ruin it.'''