Joe, 87, got a high fever while having tests done, but doctors aren't sure what is wrong with him, reported TMZ.
Joe's son Jermaine Jackson, brother of the singing legend Michael, confirmed his father was rushed to hospital and admitted the family were "worried" about his wellbeing.
"My father is doing much better. We were all worried but he's doing much better, he's much healthier and we're very happy about that. He got weak and they rushed him ... He was doing a normal check-up and he got weak and they admitted him," Jermaine said.