Democratic presidential candidate Hillary Clinton has canceled a campaign trip to California because of her diagnosis of pneumonia, a campaign official said on Sunday.
Hillary Clinton's health came under fresh scrutiny on Sunday when her doctor diagnosed her with pneumonia and dehydration after she suddenly left a 9/11 memorial ceremony Sunday.
The Democratic White House hopeful cancelled a campaign fundraising trip to California in which she was due to leave on Monday morning for a two-day swing that included fundraisers and a speech on the economy.
The timing could not be worse for the 69 year-old Clinton. With less than eight weeks to go until the general elections and two weeks left before the first of three presidential debates, Sunday's incident at Ground Zero is sure to fuel Donald Trump's insinuations that she is not healthy enough to lead.
Clinton had been seeking to bounce back from a blunder on Friday, when she told donors that half of Trump's supporters belonged in a "basket of deplorables".
The former secretary of state was at the high-profile ceremony at Ground Zero in Manhattan for 90 minutes and greeted some family members of those killed in the deadly terror strikes 15 years ago, her campaign said in a statement.
"During the ceremony, she felt overheated so departed to go to her daughter's apartment, and is feeling much better," the statement said.
Later, the campaign released a statement from her personal doctor, Lisa Bardack, who revealed that Clinton had been diagnosed with pneumonia Friday and was suffering from dehydration.
"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," Bardack said.
"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."
A campaign aide said Clinton had been examined at her home in Chappaqua, New York, after leaving Ground Zero.
A video posted on Twitter showed Clinton, wearing a blue suit and white blouse, seeming unsteady as she waited to get into a black van to leave the emotional 9/11 service.
She appeared to stumble as she was helped into the vehicle, and had to be held up on either side by members of her entourage.
It was a humid day in New York, with temperatures around 28 Celsius (82 degrees Fahrenheit).
Clinton reappeared a few hours later, apparently recovered as she walked out of her daughter Chelsea's home. She smiled for the media and posed for pictures with a young girl before departing in a vehicle for her home in Chappaqua.
"I'm feeling great, it's a beautiful day in New York," Clinton said.
Clinton's pneumonia diagnosis follows a wave of conservative conspiracy theories that circulated in recent weeks suggesting that Clinton's coughing was a sign of deeper problems.
Clinton's speech at a campaign rally earlier this month in Cleveland was interrupted by a coughing spell. During the speech, she quipped, "Every time I think about Trump I get allergic." She then resumed her speech.
Trump, 70, has said Clinton is "not strong enough to be president" and that she "lacks the mental and physical stamina to take on ISIS."
The root of the claims lies in 2012, when Clinton was nearing the end of her stint as secretary of state and a stomach virus and dehydration prompted her to faint, causing what her doctor said was a concussion.
They said they found a blood clot on the brain and Clinton temporarily suffered from double vision. She was later given the all-clear.
The former first lady has dismissed "conspiracy theories" about her health and points to a letter from her doctor declaring her fit to serve as president.
Larry Sabato, a veteran political scientist at the University of Virginia, said Clinton's team should release a full health record.
"We really haven't gotten very much, essentially a letter from her doctor," he told CNN, but added that Trump should be held to the same requirement.
A Washington Post-ABC News poll out Sunday shows Clinton leading Trump 46 percent to 41 percent among likely voters.