Sharon Osbourne is "thinking of" Catherine, Princess of Wales, as she goes through cancer treatment.

The 71-year-old star battled colon cancer in 2002 and found the impact of chemotherapy to be "devastating", so she has a lot of sympathy for the princess, who recently announced the disease had been found after she underwent abdominal surgery in January, and her and Prince William's young children Prince George, 10, Princess Charlotte, seven, and Prince Louis, four, because she can still remember the "fear" in the eyes of her own kids, Aimee, 40, Kelly, 39, and 38-year-old Jack.

Sharon told The Times magazine: "I went through cancer in 2002, so I’m thinking of the Princess of Wales.

"Chemo is not fun. I lost my fingernails, toenails, hair. I think about her beautiful hair, her body and what chemo does to your body. It’s devastating.

"I think of her children, because when I told mine, there was fear in their eyes. My three all dealt with it differently. It’s a huge responsibility for a parent to see what it does to your children."

Sharon's husband Ozzy has Parkinson's disease and she has found it "devastating" to watch him struggle with the neurological condition, knowing there is nothing she can do to help.

She said: "Ozzy’s Parkinson’s has been very difficult. It breaks your heart to see somebody you love and adore not being 100 per cent. You feel helpless because you want to help them get better, but there’s nothing you can do. It’s completely devastating."

When it comes to her own health, the former 'X Factor' judge has been taking antidepressants for decades and though she wishes she was "stronger", she knows she needs the help they give her to keep functioning.

She said: "I’ve been on antidepressants for more than 30 years. I often think to myself, God, why can’t I be stronger? Why do I need to take this?

"But it’s just a fact of life. I’d much rather lie in bed and pull the sheets over my head. But I can’t, so I need constant medication."