US Democratic presidential candidate Hillary Clinton has cancelled a campaign trip to California after being diagnosed with pneumonia.
Mrs Clinton was taken ill on Sunday at a 9/11 memorial ceremony, stumbling as she left the event early.
The candidate’s team said she was diagnosed with pneumonia on Friday and given antibiotics, but had become dehydrated at the New York event.
Her doctor said she was now re-hydrated and “recovering nicely”.
Mrs Clinton was due to leave for California on Monday morning for a two-day trip that included fundraisers and a speech on the economy.
Her personal physician, Dr Lisa Bardack, said: “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. She was put on antibiotics, and advised to rest and modify her schedule.”
On Sunday, video showed Mrs Clinton being supported by aides as she entered a van to leave the 9/11 ceremony.
She was taken to her daughter’s flat nearby and her team said she was “overheated”. The candidate re-emerged later on Sunday, telling reporters: “I’m feeling great. It’s a beautiful day in New York.”
She then left for her home in Chappaqua, New York.
Mrs Clinton’s Republican opponents have queried her physical fitness. Presidential candidate Donald Trump told his supporters last month she “lacks the mental and physical stamina” to serve as president and to fight the so-called Islamic State.
Mr Trump’s team has not yet made any comment on Mrs Clinton’s pneumonia diagnosis.
Last month, Dr Bardack said the candidate was “in excellent health and fit to serve as president of the United States”. She made a full recovery from surgery she underwent in 2012 for a blood clot, the doctor added.
The Clinton campaign has accused opponents of pushing a “deranged conspiracy about Clinton’s health”. Mrs Clinton is 68. Her Republican opponent Donald Trump is 70.
Analysis – Anthony Zurcher, BBC News, Washington
George HW Bush once vomited on a Japanese prime minister. His son fainted in the White House after choking on a pretzel. Franklin Roosevelt hid his serious health conditions, and John F Kennedy never spoke of his debilitating back condition.
The difference between these men and Hillary Clinton, however, is that her “overheating” episode – the apparent result of a case of pneumonia – comes in the home stretch of a presidential campaign where she seeks to tie Ronald Reagan as the oldest person ever elected to a first term as president.
Then there are the conspiracy theories about her health – some advanced by top Trump campaign surrogates – which will become more frenzied. The campaign’s decision to reveal Mrs Clinton’s pneumonia diagnosis only after her very visible struggles two days later will certainly complicate matters.
Donald Trump, age 70, is not clear of medical concerns of course. The only information on his health comes from a haphazardly written note from his doctor.
Sunday’s episode may keep Mrs Clinton off the campaign trail for a few days, then fade away. People who would otherwise have shrugged off her health rumours, however, are now watching her activity more closely.
What the US press said
Writing in the Washington Post, Todd C Frankel said Mrs Clinton had for years been discreet about her medical history and her discretion “made it difficult for voters to assess her complete health picture”.
NBC News reporters said the incident had “sparked renewed calls for both Clinton and Trump, who are 68 and 70, respectively, to reveal more about their health”.
Adam Nagourney, New York Times LA Bureau Chief, tweeted: “Is this hadn’t happened, would Clinton campaign have announced pneumonia? One reason why Clinton/Trump should release medical records.”
Vox News pointed out that the US has a rich history of presidential candidates being less than clear about their medical histories. “Looking back, we now know a number of past presidents and presidential candidates who have actually been much sicker than the public knew.”