Donald Trump's attack of sniffles during presidential debate prompts questions about his health

It came even as Trump questioned Clinton's 'stamina' to be president

Donald Trump suffered a severe attack of the sniffles during the historic first TV debate of the 2016 presidential campaign, as 100 million people tuned in to watch his clash with Hillary Clinton.

Normally, that wouldn't receive more than a passing mention. But in an election dominated by health issues, where Mr Trump has declared himself the "healthiest candidate ever to run for president" and where his supporters have analysed each Clinton cough as a sign of something more serious, the sniffles got noticed.

Trump's campaign team was quick to deny he had a cold in the aftermath of the debate, which touched on serious issues such as racism, Isis and Mr Trump's tax returns.

But the unfortunate timing of the sniffles onset - even as Mr Trump reiterated his view that Ms Clinton "doesn't have the stamina" to be president - was too good for many on the left of the debate to resist.

Parody accounts Donald's Sinuses (@TrumpsSinuses) and Trump Sniff (@TrumpSniff) sprang up, and quickly gained a large following. Mashable published an edited version of the 90-minute debate consisting only of sniffs.

At 68 (Clinton) and 70 (Trump), the candidates have the greatest combined age of any presidential head-to-head in history. If Mr Trump were to win in November, he would be the oldest president ever elected.

Yet while the gruelling campaign will surely have taken a toll on both sides, it has until now only really been Ms Clinton's health in the spotlight. Earlier this month she was filmed collapsing at an event to commemorate the victims of the 9/11 attacks, and her team was later forced to admit she had been diagnosed with pneumonia.

Conspiracy theories about Ms Clinton's health have abounded among Trump supporters, and the candidate himself has added fuel to the fire, suggesting Ms Clinton doesn't have "the presidential look".

Asked to clarify those comments in the debate, Mr Trump said: "She doesn't have the look. She doesn't have the stamina, I said she doesn't have the stamina, and I don't believe she does have the stamina."

Ms Clinton responded: "As soon as he travels to 112 countries and negotiates a peace deal, a cease fire, a release of dissidents, an opening of new opportunities in nations around the world, or even spends 11 hours testifying in front of a congressional committee he can talk to me about stamina."

She added: "He tried to switch from looks to stamina, but this is a man who has called women pigs, slobs and dogs."

Twitter said the debate was the most tweeted-about political moment in the social media company's history. Trump was the focus of 62 percent of the conversation on the social media platform.

The most tweeted-about topics were the economy, foreign affairs, energy and environment, terrorism and guns.

Additional reporting by agencies