The 'Believe' hitmaker, who is on a 25million pounds contract in Las Vegas, has been suffering from a severe breathing complaint. Thereby, doctors have told her to rest until at least January.
At first it was being believed that the 62-year-old was suffering from "Vegas throat", caused by the dry desert air.
However, Cher's spokeswoman Liz Rosenberg confirmed the star had fallen victim to asthma-related bronchitis.
"Asthmatic bronchitis worsens over the years. The person becomes increasingly open to infections that further weaken the immune system, possibly becoming life-threatening," the Daily Express quoted a US health expert, as saying.
Cher was forced to cancel several shows in September but bravely returned to work last month before being ordered to call a halt. Some fans realised she was suffering on stage.
One posted an internet message saying: "She sounded very raspy. You could tell she was having difficulty."
Cher may have worsened her condition by rushing back to please her fans, according to a source at Caesar's Palace in Las Vegas.
She said: "She's the ultimate crowd-pleaser and it really hurts her when she feels she's let people down. Hitting the theatre again in October wasn't a good idea because it's hindered her recovery and possibly aggravated her condition."
It was also claimed that Cher was broken-hearted after her romance with Tim Medvetz, 24 years her junior, ended in September. The couple were said to have been planning their wedding before mountaineer and biker Medvetz broke off the relationship.