Hillary Clinton’s latest coughing fit has again raised questions on the campaign trail about the state of her health.

On Tuesday, Clinton was consumed by coughing for about three minutes during a speech in Harlem, New York.

She suffered through a similar coughing episode on January 25 during a speech in the run-up to the Iowa Caucus.

The Harlem audience began chanting “Hillary” over and over to give the Democrat presidential candidate some encouragement as she fought to regain her composure.

Clinton showed up wearing glasses today during a campaign stop at Ceasars Palace in Las Vegas. She was apparently last seen wearing glasses publicly in January 2013 during testimony on Capitol Hill following treatment for blood clots. “It is thought Clinton was wearing a Fresnel prism on her spectacles — a stick-on panel often used to treat double vision,” the Daily Mail claimed at the time.

WATCH: Hillary Clinton struggles getting through a speech yesterday due to a coughing fit that lasted nearly 4 min. https://t.co/sQZ0CIo2A7 — Good Morning America (@GMA) February 17, 2016

In July, her campaign released medical records pronouncing her sufficiently healthy to serve as president and that also indicated that the Democratic front-runner in election 2016 is taking medicine for an underactive thyroid as well as another prescription for the above-mentioned blood clots following a concussion suffered in December 2012.

“Clinton had a similar moment during her lengthy Benghazi Select Committee testimony in October, briefly halting the proceeding when she began coughing almost uncontrollably and needed a cough drop,” the Washington Free Beacon recalled following the Iowa episode.

Matt Drudge, the proprietor of the high-leverage Drudge Report, claims that the media is covering up the fact that Hillary Clinton is suffering from hypthyroidism/Hashimoto’s disease, although coughing is not included in the list of symptoms.

A doctor told Inside Edition that Hillary Clinton may have acid reflux in the throat.

As the Inquisitr previously reported, Hillary Clinton’s brain concussion was said to be the result of a stomach virus the former U.S. Secretary of State acquired while traveling abroad. She returned home dehydrated and fainted, hitting her head. For a while, it caused her to need those special glasses, and raised health concerns. Bill Clinton revealed that it had taken six months of serious work for her to recover fully.

With same “low energy” linguistic kill shot (a term coined by Dilbert creator Scott Adams who is closely following the campaign) that undermined Jeb Bush’s chances, GOP front-runner Donald Trump questioned Hillary Clinton’s health during an Iowa rally in December.

“She’ll do a couple of minutes in Iowa, meaning a short period of time. And then she goes home. You don’t see her for five or six days. She goes home, goes to sleep. I’m telling you. She doesn’t have the strength. She doesn’t have the stamina.”

On NBC’s Meet The Press, Trump insisted that “Hillary’s not strong, Hillary’s weak, frankly. She’s got no stamina, she’s got nothing.”

In an interview with ABC News anchor (and former Bill Clinton political operative) George Stephanopoulos, on This Week, Clinton, 68, laughed off Trump’s lack-of-stamina charge. At an Iowa campaign event, Clinton declared that “I’ll match my endurance against anybody. And last spring, my doctor put out a letter and you know, said what great health.”

Ironically perhaps, Clinton, 68, is trying to fend off a surprisingly strong challenge from Vermont Senator Bernie Sanders, a spry 74, and a self-described socialist who is running for president as a Democrat. According to current polling data, Clinton and Sanders are in a virtual dead heat in both South Carolina and Nevada, which is leading some observers to wonder if she is “choking away” the nomination, one in which she originally enjoyed a big lead.

“In December 2012 Clinton fell at home and suffered a concussion; subsequent exams discovered blood clots. Since then, Clinton has been treated with blood thinners but it is her recent spate of coughing fits…that is beginning to raise the health question once again,” Truth Revolt summarized.

According to author and Clinton foe Ed Klein, Hillary Clinton “has been “frequently plagued’ by ‘blinding headaches’ and a series of strokes over the course of the campaign which have left her second-guessing her chances of winning in 2016,” the New York Post reported in September 2015. Klein’s book also claims that Hillary Clinton suffers from insomnia, exhaustion, and depression.

In a campaign rally in Nevada this week, Hillary Clinton had enough voice left to bark like a dog, however.

Hillary Clinton literally barks like a dog in effort to attack GOP https://t.co/b7JDvqMQCehttps://t.co/d6Bty5vg6u — FOX & Friends (@foxandfriends) February 16, 2016

Do you think there is any substance to speculation/rumors about the status of Hillary Clinton’s health and stamina necessary to serve as president of the United States?

[Photo by Charles Rex Arbogast/AP]

Added: Hillary Clinton had another coughing fit On March 6 during the nationally televised debate against Senator Bernie Sanders in Flint Michigan.

“It was an amazing juxtaposition last night. The Democratic presidential debate ended with Hillary Clinton going into yet another of her many coughing fits which was immediately followed on CNN by their new series, ‘Race For The White House,” in which the coverup of John F. Kennedy’s health problems was prominently featured. This coughing fit, along with her hoarse voice during the debate, has continued to fuel speculation on the real state of Hillary’s health although we have been assured via much of the mainstream media that there are no real problems in that area,” NewsBusters explained.