The president checked into a Manhattan hospital for tests early in the day after suffering chest pains. An angiogram revealed that the president needed surgery to repair blocked arteries.
"He was admitted to Columbia Presbyterian hospital ... and is scheduled to have bypass surgery," his wife, Sen. Hillary Rodham Clinton, D-N.Y., said Friday. "He went to our local hospital yesterday complaining of chest pains and shortness of breath."
Speaking at the New York State Fair in Syracuse, Clinton said her husband returned to the hospital early Friday morning for additional tests and doctors advised him to undergo the surgery as soon as possible.
A Democratic official said Mr. Clinton, 58, had not suffered a heart attack but said initial tests revealed "significant blockage," according to the Associated Press.
The former president was scheduled to join his wife on a two-day trip across upstate New York but was forced to cancel the trip. Sen. Clinton and the couple's daughter Chelsea planned to head to New York City to be with the former president.
President Clinton also had plans to campaign for Democratic presidential candidate John Kerry, the AP reported. Speaking from a campaign rally in Newark, Ohio, Kerry said Mr. Clinton is "going to be fine."
"But every single one of us wants to extend to him our best wishes, our prayers and our thoughts and I want you all to let a cheer out and clap that he can hear all the way in New York," he told attendees.
In Little Rock, Ark, near Bill Clinton's hometown, his mother-in-law Dorothy Rodham said she had spoken to him.
"He sounded wonderful as usual and very upbeat, as he always is," she said. "I just told him how much I love him."
His stepfather Dick Kelley said Mr. Clinton had called him to try to warn him about the situation before the press found out.
"He was very gung-ho and optimistic about what's going to happen," the AP quoted Kelley as saying.
During his term as the country's 42nd president, Bill Clinton was known for his penchant for junk food. Tests done soon after he left office in 2001 revealed that the former president had above-normal cholesterol levels and borderline high blood pressure, according to CNN.
Since then, however, President Clinton made an effort to lose weight, admitting on the Oprah Winfrey show that he was on the popular South Beach diet and was working with a trainer.
Prior to this, the only other health problems Mr. Clinton has had relate to skin cancer. In early 2001 doctors removed a cancerous growth from his back and in 1995 and 1996 he had a benign cyst removed from his chest and a precancerous lesion taken off his nose, according to the AP.
Doctors also fitted the former president with hearing aids in 1997.
On Friday, Reuters reported that throngs of camera crews and other media had set up camp outside New York-Presbyterian Hospital, commonly known as Columbia Presbyterian, north of the former president's Harlem office. The hospital is one of the nation's best cardiac hospitals, the report said.