Democratic presidential candidate Hillary Clinton abruptly left a 9/11 memorial event at Ground Zero Sunday because she is overcoming pneumonia, her doctor said.

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Dr. Lisa R. Bardack diagnosed Clinton with pneumonia on Friday, according to ABC News.

"Secretary Clinton has been experiencing a cough related to allergies," Bardack said "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. 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."

>>Read Hillary Clinton stumbles, leaves 9/11 memorial service early