Hillary Clinton’s health issues are drastically worse than she has revealed publicly — and the potential presidential candidate tried to keep her medical information private for fear that it would damage her bid for the White House in 2016, according to a new book.

The 66-year-old former secretary of state has suffered more fainting spells than publicly known, is prone to have blood clots, and may be at serious risk of a stroke, according to the book, “Blood Feud: The Clintons vs. the Obamas,” by Edward Klein.

The medical scare that forced Clinton to be rushed to New York-Presby­terian Hospital on Dec. 30, 2013, revealed how serious the situation is.

“She has to be carefully monitored for the rest of her life,” doctors warned former President Bill Clinton before Hillary was released from the hospital, according to the book.

The book claims Hillary was taken to New York­Presbyterian after a fainting spell and concussion that she suffered in her seventh-floor office at the State Department — not at her home, as claimed.

Hillary was initially treated at a State Department facility and was transferred to her home to recover. Bill Clinton, however, insisted Hillary be flown to New York City and be treated by specialists there, Klein claims.

During her visit to the Manhattan hospital, the presumed 2016 Democratic front-runner was diagnosed with several problems, including the clots.

Hillary had a right transverse venous thrombosis, or a blood clot, between her brain and skull.

“The unique thing about clotting in the brain is that it could have transformed into a stroke,” a cardiac specialist with knowledge of Hillary’s condition says in the book.

The clots are especially a threat while flying, when blood pools while sitting, and she did a lot of flying while at the State Department.

In addition to a 2005 fainting spell during a speech in Buffalo, Hillary also fainted while boarding her plane in Yemen in 2009, which caused her to fall and fracture her elbow.

Meanwhile, coming after Hillary’s recent comments that she was “dead broke” when she left the White House, she played the poor card again, telling The Guardian that she is not “truly well off” when compared to the super rich.

“We pay ordinary income tax,” she told the paper, “unlike a lot of people who are truly well off, not to name names; and we’ve done it through dint of hard work.”