Chappelle was performing at the Punch Line Comedy Club "and at the time he did it, he did not get enough water to drink and had a little bit of dehydration," Laugh Factory owner and friend Jamie Masada told E! Online Tuesday.
Masada said Chappelle spent about 12 hours at the hospital, where he received food and fluids.
"He's so thin, and he gets so creative he forgets to eat and drink," Masada said. "I've known him since he was 15 years old. His biggest problem is he gets in a creative mode and forgets to eat. He's on the stage for six or seven hours. Everybody would have a bottle of water and he'll have nothing."