Was Donald Trump sick at Monday night's first presidential debate? Many viewers thought so, and as such, the #TrumpSniffle hashtag was born.

It was pretty clear early on in Monday's debate that Trump was having some kind of breathing problem. During many of his responses, he was heard sniffling rather loudly, prompting Twitter to do what it does best: create a viral hashtag.

From people thinking he had a cold to others who thought the sniffling was some type of secret message, here were the best responses to come out of Twitter last night:

The #TrumpSniffle comes at an ironic time given Trump's recent claims about health and stamina. The Republican presidential nominee noted that his opponent, Hillary Clinton, may be too unhealthy to serve after she fainted at a 9/11 event. He also said during the debate that Clinton didn't have "the stamina" to successfully serve as president.

The health of both Clinton and Trump has been an issue raised by many voters and the candidates themselves throughout this race. At 70 years old, Trump would be the oldest president in American history while 68-year-old Clinton would be the second oldest.

However, Trump's doctor, Harold Bornstein, released a statement about his health back in December, stating that "If elected, Mr. Trump, I can state unequivocally, will be the healthiest individual ever elected to the presidency." The doctor said that Trump's health was "astonishingly excellent," his "physical strength and stamina are extraordinary," and he had apparently lost 15 lbs. over the past year.

Trump followed this statement with his own, noting, "People have been impressed by my stamina, but to me it has been easy because I am truly doing something that I love."

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