Supermodel Cindy Crawford says she sometimes feels "overwhelmed" by the expectations of the fashion industry.

In an extract from her new book, Becoming, Crawford, who turns 50 next year, said she finds ageing tough as she has relied on her looks for her career path, reported Daily Mirror.

"Having been a model now for more than 30 years and dependent on my looks for my work, seeing those changes (as I age) might even be a little bit harder for me.

"At times the pressure to live up to the fashion industry’s expectations feels overwhelming. I can still pull off a miniskirt and five inch heels on set – but probably not in real-life." 

The supermodel believes it is only her "real life" persona that is ageing as her modelling one is part of an "illusion".

"Sometimes I forget that the images I am used to seeing of myself aren’t real, that they are all part of the illusion of being Cindy Crawford.

"And then I will catch a glimpse of the real, unretouched Cindy or see an unflattering paparazzi shot, and it’s a shocker."