The 85-year-old ex-president left the hospital at 1:15 p.m. and will resume his schedule with a meeting this week in Washington, D.C., said Eileen Korey, spokeswoman for MetroHealth Medical Center. He was headed to Washington, Carter spokeswoman Deanna Congileo said.
Carter, smiling and carrying a briefcase, paused briefly outside the emergency room to wave to bystanders. Dressed in a blue blazer and gray slacks, he waved again as his motorcade drove off. About 15 minutes later, he flew out on a private jet.
"He thanked his medical team at MetroHealth for the attentive and comprehensive care and treatment he received during his stay," Korey said. "He also again expressed his appreciation to all the members of the public who sent greetings to him."
Carter became ill during a Delta Air Lines flight Tuesday from Atlanta to Cleveland, causing rescue crews to rush him to the hospital after the plane landed. His medical team recommended that he stay for two nights for monitoring.
The hospital stay interrupted Carter's tour to promote his new book, "White House Diary." Planned book-signings in Ohio and North Carolina on Tuesday, in Washington on Wednesday and in South Carolina on Thursday were all canceled.
Carter, a former peanut farmer elected to the White House in 1976, has spent his recent years pursuing peace and human rights, efforts that won him the Nobel Peace Prize in 2002.
In the new book, Carter said he pursued an overly aggressive agenda as president that may have confused voters and alienated lawmakers. But he said the tipping points that cost him the 1980 election were the Iran hostage crisis and the Democratic primary challenge by U.S. Sen. Ted Kennedy.
He is the author of more than 20 books, including the "Palestine Peace Not Apartheid" in 2006, about his experiences in the Middle East, and 2005's "Our Endangered Values: America's Moral Crisis."