Hillary Clinton's diagnosis of pneumonia will be "highly significant" to her campaign, according to leading doctor Laurence Gerlis.
The Democratic presidential candidate was filmed collapsing in New York City as she left an event to commemorate 9/11, with the cause later revealed to be pneumonia.
Dr. Gerlis, a GP and the founder of Samedaydoctor, explained the seriousness of the illness to listeners, and how it could have a very real impact on her campaign.
"It's potentially fatal if not diagnosed and treated properly," he told Julia Hartley-Brewer. "It's an infection of the material in the lung, so you can get consolidation or collapse of the whole body of the lung. You can treat it in the community, but it's certainly a cause for concern.
"Clearly Hillary Clinton will get first-class medical care, but the Americans take these things very seriously, because the President is head of state and government with a nuclear arsenal. It's a very open society, their medical records are really public property.
"So I wouldn't be surprised if this makes a huge turning point in the American election campaign, it's highly significant. They're [Hillary Clinton and Donald Trump] both getting on the old side for public office, it's hugely demanding.
"68 and 70 is a bit old for a very demanding and grueling job."