Hillary Clinton has a heart valve problem and turned down advice from her doctors to have surgery in order to avoid any public fallout from it, author Ed Klein said Monday night.

Klein, the author of "Guilty as Sin: Uncovering New Evidence of Corruption and How Hillary Clinton and the Democrats Derailed the FBI Investigation" spoke with Sean Hannity on Fox News regarding his new book about the Clintons.

After confirming Clinton has an irregular heart beat, Klein said her health problems are far worse.

"She has a heart valve problem. The doctors wanted to replace the valve and she didn't do it," Klein said.

When Hannity followed up by saying a doctor would discuss with a patient fixing a heart valve condition via surgery, Klein said that conversation took place.

"They did and she said no because she was worried if she had, it would leak out that she had a surgery and that would somehow undercut her presidential race."

Klein did not give a specific timeline as to when the heart valve problem was discovered.

In "Guilty as Sin," Klein also discusses former President Bill Clinton and said he continues to get physical with interns — now from the Clinton Library in Little Rock, Arkansas.

"Twenty-something-year-old interns, giving him foot massages in his penthouse apartment in Little Rock," Klein said. "You can't make this stuff up.

"I've interviewed these women who did it. Touching the president is very thrilling is what they say."

Regarding Hillary Clinton's presidential aspirations, Klein said "everyone understands that she's corrupt." Clinton, according to the latest RealClearPolitics polling average, is up 3.1 points on Republican Donald Trump.

"Guilty as Sin" is available Tuesday.