Dr Lisa Bardack said she was diagnosed with pneumonia on Friday, given antibiotics but had become dehydrated.
Dr Lisa Bardack said she was diagnosed with pneumonia on Friday, given antibiotics but had become dehydrated at the event, BBC reports.
"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," Dr Bardack's statement said.
"She was put on antibiotics, and advised to rest and modify her schedule," it added.
A campaign official said she has cancelled a campaign trip to California due to the illness.
Clinton was expected to leave for California on Monday morning for a two-day trip that included fund raisers and a speech on the economy.
The 68-year-old US Democratic presidential candidate has for some time now had her Republican opponents questioning her about her physical fitness.
Her campaign has subsequently accused opponents of pushing a "deranged conspiracy about Clinton's health".
Dr Bardack, however, said last month that Mrs Clinton was "in excellent health and fit to serve as president of the United States".
Mrs Clinton made a full recovery from surgery she underwent in 2012 for a blood clot, the doctor added.