Twiggy thinks modelling is to blame for her "dodgy" back.
The '60s fashion icon, whose real name is Lesley Lawson, believes all those years of strutting down the runway during the height of her career has had a knock-on effect on her health and has now left her bedridden with sore bones.
She explained: "My back's a bit dodgy from all those years of modelling - walking around in high heels and sticking your bottom out does terrible things."
And, although she would probably quite like a new back because she's fed up of being in pain, one thing she won't be getting rid of any time soon is her wrinkles.
The 66-year-old model is adamant she'd never go under the knife or have Botox injections to plump up her face and eliminate her lines because she's proud of her age.
She said: "I think people are starting to get sick of their faces not moving. I don't understand why anyone would want to be a 70 year old with a 30 year old face. I'm proud of my wrinkles, I have earned them, after all."
Meanwhile, she may have just had her 66th birthday but Twiggy certainly shows no signs of slowing down.
Speaking to the Daily Mirror newspaper, she said: "It's funny, because older women are so stylish now. It was so different for my mum's generation, they just weren't into fashion and clothes, they just dressed appropriately."