WASHINGTON (Reuters) - It was classic Hillary Clinton, ignoring medical advice and attending a ceremony on a sultry New York City day while battling pneumonia - a decision ex-aides and other associates speculated was rooted in her longstanding desire to prove that women can compete in the male-dominated world of politics.

U.S. Democratic presidential candidate Hillary Clinton and New York Mayor Bill de Blasio (R) attend ceremonies to mark the 15th anniversary of the September 11 attacks at the National 9/11 Memorial in New York, New York, United States September 11, 2016. REUTERS/Brian Snyder

The move backfired on the famously stoic Democratic presidential candidate after she had to leave Sunday’s September. 11 remembrance early and was caught on camera buckling from dehydration as she was helped into a van.

Clinton, 68, has since acknowledged she went too far in trying to soldier on with a jam-packed schedule.

Daniel Scherb, a South Bend, Indiana, cardiologist interviewed by Reuters, who was not privy to Clinton’s medical records, said pneumonia can leave a patient “feeling blah for seven to 10 days” under the best of circumstances and, at worst, “people can die from it.”

Former subordinates who are fiercely loyal to Clinton said there are plenty of instances in which she drove herself remarkably hard as first lady from 1993-2001, as a U.S. senator from 2001-2009 and as U.S. secretary of state from 2009-2013.

In her first year at the State Department in 2009, she traveled abroad extensively shortly after undergoing surgery for a broken arm.

One retired ambassador said Clinton sees herself as part of a generation of women who had to work extra hard to overcome barriers to female advancement. The ambassador describes this as part of an ethos that “you could never be weaker than a man.”

At the same time, the ambassador blamed Clinton’s aides in part for allowing her to put herself into difficult situations.

‘A DIFFERENT LENS’

At an event in Congo after breaking her arm, Clinton snapped at someone who posed a question she disliked, the ambassador recalled. While the question may have been translated into English incorrectly, the ambassador said Clinton also was clearly exhausted.

“It’s not necessarily that she is running roughshod over the advice of her staff. Her staff doesn’t seem to take very good care of her,” the ambassador said.

Working to defeat Republican presidential candidate Donald Trump, 70, on the rough-and-tumble campaign trail, Clinton has said she is held to a different standard.

“Women are seen through a different lens,” Clinton told Humans of New York, a group organized around a project to photograph and catalog stories of New Yorkers.

“I’ve learned that I can’t be quite so passionate in my presentation,” she said, adding, “I love to wave my arms, but apparently that’s a little bit scary to people. And I can’t yell too much. It comes across as ‘too loud’ or ‘too shrill’ or ‘too this’ or ‘too that,’” even though those attending her rallies “are loving it.”

In all her roles, including as President Bill Clinton’s healthcare chief and a two-time presidential candidate, Clinton has been known as an almost unstoppable, detail-oriented policy wonk.

“Her constant work, internal in meetings or external on Capitol Hill, was virtually incomprehensible,” said David Dreyer, a White House deputy communications director during Bill Clinton’s first term.

Dreyer, who said he had a “front row seat” to the healthcare reform fight that Hillary Clinton spearheaded as first lady, said she is “wired” to always be fully prepared and compelled to public service.

‘CAN’T-WIN SITUATION’

Three other people, one close to Clinton when she was secretary of state and as a presidential candidate, said efforts to persuade her to temper her travel and appearance schedule can go nowhere because she insists it is expected of her.

One, a prominent former official who has advised Clinton on foreign policy issues, said: “She pushes herself so hard because she’s convinced that only she can do what needs to be done, and that’s compounded by a very small inner circle that in some cases doesn’t like to contradict or confront her, and as a result just ends up encouraging this compulsion.”

Matt Bennett, who served as deputy assistant for intergovernmental affairs in Bill Clinton’s second presidential term, said Hillary Clinton is “in a can’t-win situation here.” Noting competing, unsubstantiated attacks from Trump and his supporters about her health versus criticisms that she does not know how to pace herself, “Either she is frail or reckless with her health.”

Bennett added, “I don’t view her as disregarding medical advice” over past blood clots, a fall that caused a concussion and other maladies. “But I do think she’s super tough.”

Bennett, now a vice president at the Third Way think tank, said the increasingly frantic pace of campaigning for the White House has pressed candidates to the limit.

As an aide to retired General Wesley Clark while he unsuccessfully sought the Democratic presidential nomination in 2004, Bennett noted that Clark would constantly remark about the rigors of the campaign. “He was shot multiple times in Vietnam and went through (elite Army) Ranger training and he’s saying this is really tough running for president.”