This Morning's resident agony aunt Denise Robertson has been diagnosed with cancer.
The writer and broadcaster, 83, said: "I'm sorry I've not been around for a couple of weeks but a persistent health issue has turned into something quite a lot bigger.
"I've been diagnosed with pancreatic cancer. It has come as a surprise to me and my family but we know that many others have suffered and dealt with this condition and I don't plan to give up without a fight. My doctor is referring me for chemotherapy and hopefully that will start soon.
"I'd like to thank all the lovely viewers of This Morning who have been concerned about my health recently and I hope I'll be back on the sofa soon."
Robertson, from Sunderland, joined ITV's This Morning for its first ever broadcast in 1988. She also has her own advice website, and has written a column for Candis magazine.
Presenter Ruth Langsford told viewers: "Some news about one of our own that has all of us at This Morning in a state of shock.
"After almost 30 years of providing comfort to millions of This Morning viewers, agony aunt Denise Robertson is in need of a lot of love herself today."
Her co-host Rylan Clark called on fans to send messages of support, as Robertson - who is not known for being tech-savvy - "does know how to read Facebook comments".
He suggested that well-wishers could send messages through the This Morning Facebook page.
Robertson lost her first husband Alex Robertson to lung cancer in 1972.
In 2006 her stepson, John, also died of cancer, at the age of 44.
Within 20 minutes of the announcement, over 2,000 messages of support had been posted under the statement on Twitter.
Maria Shankland, who said she was fighting lung cancer, commented: "Let's show cancer we can do it! It does not rule us!!! Good luck with your treatments. Positive thoughts sent your way."
Facebook user Danielle Kerstein said: "You have given hope and prayers to so many people. I'm sure everyone reading this will send heaps of prayers and love back to you. You are an angel on this planet. Keep fighting."
Luke Stevens wrote: "Absolutely adore this lady, so fair and wise. Beautiful woman inside and out I've said my prayers for her to get better.
"Wishing her all the love and support, get well soon beautiful keep fighting like I know the strong woman you are."