Arians, 60, was hospitalized with an undisclosed illness Saturday before the Colts' AFC wild card playoff loss to the Ravens.
The newspaper, citing a source with knowledge of the situation, said Arians was released Monday from the University of Maryland Shock Trauma Center where he had been extensively tested.
The source said all tests were negative, and that Arians was returning home.
It's believed the coach was suffering from an inner-ear infection, the Star said.
Arians guided the Colts to a 9-3 record as acting head coach in the absence of Chuck Pagano, who was excused while battling leukemia.
Arians is thought to be a candidate for several current head coaching vacancies around the league.