Jim Boylan, who coached in Skiles' absence, said the coach was doing well.
"He's fine," Boylan said. "He'll be joining us in Portland. He has a little arrhythmia."
Skiles has been cleared to coach Wednesday night against the Trail Blazers, a team official told ESPN The Magazine's Ric Bucher.
Skiles spoke to the media shortly before the game and showed no signs of illness.
A team spokesman said Skiles was hospitalized for precautionary purposes.
Skiles, 45, is in his second year as Milwaukee's coach. Last season, he guided the team to a 34-48 record. This season, the Bucks were 15-19 going into Monday night's game.
"When something like that happens, it's bigger than basketball," Milwaukee's Hakim Warrick said. "You just have to hope for the best."
Skiles coached the Suns from 1999 to 2002 and the Chicago Bulls from 2003 to 2008.
He played 10 seasons in the league with Milwaukee, Indiana, Orlando, Washington and Philadelphia.
Information from The Associated Press was used in this report.