Aretha Franklin's spokeswoman said the legendary singer is canceling all concert dates and personal appearances through May.
Publicist Tracey Jordan said on Thursday that Franklin's "doctors have required her to do so."
The news comes several days after Jordan announced that the 68-year-old Franklin had been released from a Detroit hospital following a brief stay.
Jordan wouldn't say whether the two events are related and didn't offer any details about Franklin's condition.
One of the shows being canceled is a Christmas concert scheduled for Detroit's Fox Theatre on Dec. 9.
Ticket refunds are available from the place of purchase.
In October, Franklin canceled a concert in Charlottesville for health reasons as well and was briefly hospitalized.
On her Thursday afternoon show on Mix 92.3 FM, host Frankie Darcell played Aretha Franklin music and talked with callers about Franklin's illness.
Darcell told Local 4 the news has come as a shock.
"This is Aretha Franklin. Aretha Franklin is supposed to be OK, she's supposed to live forever," Darcell said.
Many of those calling in to Darcell's Thursday show offered prayers for the health of Aretha Franklin.