Katy Perry has revealed that she can often "snap" when under stress.

The singer is one of the biggest names in pop and as a result, she has an extremely demanding schedule.

Speaking in the October issue of Harper's Bazaar, the US star said that she often takes out her frustrations on her assistant.

Perry said: "I can snap a little bit, be a little bitchy to the couple of people around me. Tamra, my assistant, is my closest punching bag. But she’s strong and understands that I have a lot of pressure on me sometimes."

The singer added that she meditates often, but sometimes has an "act-out day about every four to six months".

She said: "I’ll have a cigarette, which I know is absolutely horrible for me, after a few drinks when I’m having a week off. I don’t do black tar heroin."

Follow us: @Pressparty on Twitter / Pressparty on Facebook.

Watch Katy Perry perform live below: