The 90-year-old actress, who has played barmaid Betty Williams in Coronation Street for 42 years, is believed to be suffering from pneumonia only a year after being hospitalised for a chest infection.
A Coronation Street spokesperson said: "Betty has been taken to hospital. We are all wishing her a speedy recovery."
An industry insider told the Daily Express: "Everyone loves Betty, she's part of the heart and soul of Corrie. We're all very worried. We know she's an elderly woman but she's always been larger than life. Everyone's keeping their fingers crossed that she pulls through."
Another source told The Sun: "Obviously we are all worried because Betty is such a huge part of the show. She's an absolute trouper and still turns up for work and puts in a flawless performance. We've all sent our love and best wishes and are hoping for the best."
The star has previously said that she would be "foolish" to quit her job on Corrie, adding: "It's working so hard that keeps me young."