NEW YORK (CBSNewYork/AP) — Hillary Clinton says she got dizzy but didn’t lose consciousness when she stumbled on the way out of the 9/11 memorial Sunday.

The Democratic presidential candidate said in an interview on CNN’s “Anderson Cooper 360” that she felt dizzy and “did lose my balance,” while waiting for the motorcade. But she felt immediately better after getting into her air-conditioned vehicle.

“I felt dizzy and I did lose my balance for a minute, but once I got in, once I could sit down, once I could cool off, once I had some water, I immediately started feeling better,” Clinton said.

She said she didn’t immediately disclose that she’s been diagnosed with pneumonia because she “just didn’t think it was going to be that big a deal.”

“It’s just the kind of thing that if it happens to you and you’re a busy, active person, you keep moving forward,” she said.

Clinton on not disclosing pneumonia diagnosis on Friday: "I just didn't think it was going to be that big a deal." https://t.co/1lGeoxkx9m — CNN (@CNN) September 13, 2016

CBS2’s Tony Aiello reported Clinton felt so strongly about attending the 9/11 memorial, she ignored her doctor’s advice to spend five days in bed.

The former secretary of state fought back against assertions that her campaign has not been transparent about her health.

“I think it’s fair to say we’ve already met the standard of disclosure of past presidential candidates like Mitt Romney and President Obama. We’ll add more information. I’ve already released information about my health in this campaign as well as 40 years of tax returns. We’ve already met a high standard of transparency,” Clinton said.

She added that she’ll be back on the campaign trail “in the next couple of days.”

Former President Bill Clinton told CBS News’ Charlie Rose that the former secretary of state suffered this type of medical episode before.

“Well if it is, it’s a mystery to me and all of her doctors,” he said, “because frequently—well not frequently, rarely—but on more than one occasion, over the last many, many years, the same sort of thing happened to her when she got severely dehydrated,” Bill Clinton said.

He added that some of her staff members have also gotten sick recently.

“She’s doing fine, she was even better last night before she went to sleep. She had a good night’s sleep she’s doing fine,” he said. “We’ve gotten all these, as you might imagine, emails and text messages and calls. A friend of ours called and left a message today, that her husband had actually just been hospitalized for pneumonia apparently there’s a lot of it going around and a bunch of her staff has gotten sick. But she’s just doing fine. She just got dehydrated yesterday.”

Hillary Clinton stayed home to rest Monday after she called off a fundraising event and the rest of her planned travel in California this week and is staying at home in Chappaqua following her pneumonia diagnosis on Friday.

COMPLETE CAMPAIGN 2016 COVERAGE

The change in her schedule came after Clinton suddenly left the 9/11 anniversary ceremony Sunday.

About 90 minutes into the ground zero ceremony, Clinton left after feeling “overheated,” her campaign said. A video then surfaced of her staggering and eventually slumping forward before being held up by three people as she was helped into a van.

Hillary Clinton 9/11 NYC pic.twitter.com/q9YnsjTxss — Zdenek Gazda (@zgazda66) September 11, 2016

Clinton then went to her daughter Chelsea’s apartment nearby and later emerged, telling reporters that she was “feeling great.”

“It’s a beautiful day in New York,” Clinton said. “Thank you.”

Several hours later, her campaign revealed she was diagnosed with pneumonia on Friday and advised to rest.

“Secretary Clinton has been experiencing a cough related to allergies. On Friday, during follow up evaluation of her prolonged cough, she was diagnosed with pneumonia,” Clinton’s physician, Dr. Lisa R. Bardack, said in a statement. “She was put on antibiotics, and advised to rest and modify her schedule. While at this morning’s event, she became overheated and dehydrated. I have just examined her and she is now re-hydrated and recovering nicely.”

Doctors say her condition, combined with Sunday’s heat and humidity, all could have contributed to her condition.

“If you’ve got pneumonia and you’re being treated with antibiotics, those can indirectly lead to dehydration,” said CBS2’s Dr. Max Gomez. “If you’ve got a warm day and you’re not drinking enough fluid, you can be dehydrated. All of those things together can easily lead to fainting.”

When Mayor Bill de Blasio saw Clinton at the 9/11 memorial ceremony, he described her as, “maybe a little tired. But nothing different than usual,” WCBS 880’s Rich Lamb reported.

De Blasio was Clinton’s campaign manager when she ran for the U.S. Senate in 2000.

“She’s a workaholic. She’s got an incredible work ethic,” the mayor said. “She rarely says no to an invitation and she pushing herself very, very hard.”

The mayor said, “There’s a bunch of conspiracy theorists trying to push the idea that there’s a health problem,” and added, “There’s no proof of that whatsoever.

However, as CBS2’s Dick Brennan reported, there are still real questions about Clinton’s condition.

“She’s resting comfortably. I think if she had her druthers, she’d already be on a plane out to California today,” Clinton campaign spokesperson Brian Fallon said.

Fallon said the campaign will be producing more medical records.

“We’re going to be releasing additional medical information about Hillary Clinton,” Fallon explained. “We’ve been in touch with her physician this morning to get those together.”

Medical experts said they still don’t know what’s causing the pneumonia, how much of her lungs are involved, and therefore, how long it may take to recover.

Donald Trump, who also attended the 9/11 ceremony, has repeatedly questioned whether Clinton is physically fit to be president.

The Republican nominee said in an interview on “Fox and Friends” Monday morning that “Something’s going on, but I just hope she gets well and gets back on the trail and we’ll be seeing her at the debate.”

He did, though, unload on Clinton after she called half of his supporters a “basket of deplorables.”

“Hillary Clinton still hasn’t apologized to those she slandered,” Trump said. “If Hillary Clinton will not retract her comments in full, then I don’t see how she can credibly campaign any further.”

Trump’s running mate, Indiana Gov. Mike Pence, also made the rounds to hammer home the same point.

“The people that are drawn to this campaign, they’re drawn to that broad-shouldered leadership of a Donald Trump, and to be subject to this kind of demeaning statement is just simply beyond the pale,” Pence said.

Clinton has apologized for saying “half of his supporters,” but not on the substance of the rest of the comment.

For weeks, Clinton dismissed questions about her health as little more than a conspiracy theory, part of a “wacky strategy” cooked up by Trump as he embraced an “alternative reality.”

But less than two months from Election Day, it was a problematic visual for Clinton as she tries to project the vigor needed for one of the world’s most demanding jobs.

“I think the transparency question with Hillary Clinton in particular, but both candidates, is what is their instinct? When no one is looking, are they telling the truth?” said “Face the Nation” moderator John Dickerson. “If that’s already your instinct, that’s only going to be exacerbated when you become president.”

Dickerson added this is the “Achilles’ heel of this campaign.”

“I think there’s the transparency question, what is there instincts at a moment like this? That is the Achilles heel of this campaign, and this goes right to the question that voters have about their trust,” Dickerson said.

The episode was also sure to fuel a vocal group of online conspiracy theorists, deemed “healthers” by some Clinton supporters, who point to videos and photos of Clinton as evidence of her poor health.

Even Democrats are criticizing the campaign for failing to disclose Clinton’s illness. Former Obama adviser David Axelrod tweeted, “Antibiotics can take care of pneumonia. What’s the cure for an unhealthy penchant for privacy that repeatedly creates unnecessary problems?”

Antibiotics can take care of pneumonia. What's the cure for an unhealthy penchant for privacy that repeatedly creates unnecessary problems? — David Axelrod (@davidaxelrod) September 12, 2016

Clinton tweeted Monday afternoon that she is “feeling fine and getting better.”

“Like anyone who’s ever been home sick from work, I’m just anxious to get back out there. See you on the trail soon,” Clinton said.

Thanks to everyone who’s reached out with well wishes! I’m feeling fine and getting better. -H — Hillary Clinton (@HillaryClinton) September 12, 2016

Like anyone who’s ever been home sick from work, I’m just anxious to get back out there. See you on the trail soon. -H — Hillary Clinton (@HillaryClinton) September 12, 2016

Trump also said he’s planning to release detailed health information from a new physical exam in the coming days.

Clinton was scheduled to attend fundraisers in California Monday and Tuesday and tape an episode of Ellen DeGeneres’ talk show.

There are reports that Clinton will appear via teleconference for her fundraiser.

(TM and © Copyright 2016 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2016 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)