The British actress has said that she is under doctor's orders to rest, over concerns that she is developing pneumonia.
During a recent interview with The Guardian, Redgrave explained that she is taking it easy before the premiere of her Broadway musical Driving Miss Daisy in the London West End later this month.
"[I have] very diminished energy with which I've got to start rehearsals," Redgrave admitted.
The actress also commented on her well-known smoking habit, claiming that it isn't something of which she is proud.
"I'm an absolute addict," Redgrave said. "I only started smoking because I read a newspaper article when I was 24 in which Francoise Sagan was asked what she had for breakfast. A cup of black coffee and a [cigarette]."
Driving Miss Daisy, which stars Redgrave opposite James Earl Jones and Boyd Gaines, will open at the Wyndhams Theatre in London on September 26.