An emergency meeting will be held between senior democrats to "consider" a replacement for Hillary Clinton after the presidential nominee collapsed following an early exit from a 9/11 memorial service, sources have claimed.

Planned campaign stops may also have to be dropped from the Democrats' candidate's schedule as she is forced to make adjustments following doctor's orders.

4 The Democrats are expected to hold a meeting to discuss a replacement candidate for Hillary Clinton, following her pneumonia diagnosis Credit: AP:Associated Press

The 68-year-old was diagnosed with pneumonia on Friday, but her illness was kept out of the public light until she fainted at the commemoration service yesterday.

The incident was caught on camera, and a video later emerged of the moment the presidential candidate's knee buckled.

Helpers can be seen desperately trying to keep her upright as she makes her way to the car, but she appears to almost fall to the floor before she is bundled into the car and whisked away.

4 The presidential hopeful was diagnosed on Friday, but the public was not made aware until she collapsed at a 9/11 memorial yesterday

MSNBC journalist David Shuster tweeted: "Clarification from dem operatives @HillaryClinton pneumonia: Expect emergency DNC meeting to CONSIDER replacement."

A campaign aid has also claimed that a trip to California may have to be cancelled after the shock health scare.

4 Credit: Twitter

Lisa Bardack, Clinton’s doctor 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.



4 Clinton's doctor Lisa Bardack revealed that doctor's advised her to modify her schedule, sparking concerns she will cancel her trip to California Credit: www.caremountmedical.com

"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."

Hillary also seemed keen to downplay the incident, as she later tried to reassure people outside her daughter's home, saying "I'm feeling great. It's a beautiful day in New York."