Sugababes star Keisha Buchanan is set to have a hernia operation.The 22-year-old singer says the band's relentless schedule has finally taken its toll on her body, and she will soon be having an operation to remove the abdominal tissue protrusion. She said: "I have a hernia that I'm going to have operated on soon. I get so stressed that I can't look at our itinerary as I get flustered and worry."I worry how I'm going to pose in pictures, what I'm going to say in interviews, I never know what we are doing - I just can't cope with it. Everyone tells me not to worry but I can't help it. That's just how I am."Keisha - who is currently topping the British singles charts with the band's new song 'About You Now' - also said her skin is suffering as a result of the stress.She added: "My main insecurity is my skin. I had chicken pox when I was 17 and now whenever I'm stressed or tired, out comes a spot attack. I've seen a lot of specialists and they've given me creams, but they don't work. I don't get depressed about my skin but it is annoying."