Keira Knightley is shocked at Hollywood's obsession with being perfect, after she was told she needs liposuction at the age of 20.

The British beauty was horrified to be told she should undergo the surgeon's knife to improve her nose and tone her physique after she sought help over some facial spots.

Knightley says, "When I was in LA I went to see a dermatologist about my skin problem and, while I was there, they told me, 'By the way, would you like your nose fixed too?' and 'We can do liposuction'.

"I replied, 'Um, no thanks, I'm only 20...so No! Just fix my spots.' I was left thinking, 'What are you trying to say?'

"I believe you can use imperfections and insecurities to get into a character. And that's useful. When we look at actors and actresses today we want them to be perfectly one thing or the other.

"And if they're not, they're ripped apart. Everybody has good days, everybody has bad days. It is impossible to be perfect."