Ford Vox is a physician specializing in rehabilitation medicine and a journalist. He is a medical analyst for NPR station WABE-FM 90.1 in Atlanta. He writes frequently for CNN Opinion. Follow him on Twitter @FordVox. The opinions expressed in this commentary are solely those of the author.

(CNN) Feeding into the alt-right narrative questioning Hillary Clinton's personal health, Sunday's near-fainting spell, caught on camera, is more than enough to make her fervent opponents a little lightheaded. The social media commentary following the episode demonstrated more glee than concern. But neither emotion is warranted.

As it turns out, fainting spells (and near-fainting) are quite commonly seen in healthy people. The information we have favors Clinton's wobbly moment as nothing unusual, particularly since we now know she's battling an infection.

The video is dramatic, showing Clinton wavering back and forth and supported by her security staff into a waiting SUV that drove her to her daughter Chelsea's nearby apartment. The Clinton team's initial poor transparency, leaving it to reporters to figure out she was MIA from a New York City 9/11 memorial event (which Donald Trump also attended) and then supplying an incomplete statement, didn't do anything to help tamp down conspiracy theories about Clinton's health.

Late Sunday, the campaign issued a statement from Clinton's personal physician Dr. Lisa Bardack reporting that she'd diagnosed Clinton with pneumonia on Friday and advised her to lighten her schedule. Bardack stated the episode occurred due to the combination of that diagnosis, dehydration and overheating.

I'd certainly agree these are all factors.

That the Clinton campaign didn't release the diagnosis of pneumonia on Friday is symptomatic of its own problems.

The video clearly shows someone who's on the verge of fainting (medically, the term for such temporary loss of consciousness is syncope , or if the person doesn't actually pass out, it's pre-syncope). Yet Clinton's spokesman Nick Merrill said the candidate "felt overheated so departed to go to her daughter's apartment." "Feeling overheated" lacks the important detail that she couldn't hold herself up on her own as she got into the waiting vehicle.

But while the Clinton campaign once again managed to foster the perception that they're preoccupied by information over-control, we shouldn't let their odd behavior get in the way of interpreting the facts we have now.

The "differential diagnosis" list, or range of potential problems to consider , when someone faints is huge. But about half the time doctors don't need to do any special testing to figure out the problem. A simple physical exam, or even the history alone (or story) of the event settles the diagnosis in such cases.

Hillary Clinton's episode Sunday looks like one of those straightforward cases, and it's not surprising Bardack is confident in the factors at play.

Photos: Hillary Clinton's life in the spotlight Hillary Clinton accepts the Democratic Party's nomination for president at the Democratic National Convention in Philadelphia on July 28, 2016. The former first lady, U.S. senator and secretary of state was the first woman to lead the presidential ticket of a major political party. Hide Caption 1 of 43 Photos: Hillary Clinton's life in the spotlight Before marrying Bill Clinton, she was Hillary Rodham. Here she attends Wellesley College in Massachusetts. Her commencement speech at Wellesley's graduation ceremony in 1969 attracted national attention. After graduating, she attended Yale Law School. Hide Caption 2 of 43 Photos: Hillary Clinton's life in the spotlight Rodham was a lawyer on the House Judiciary Committee, whose work led to impeachment charges against President Richard Nixon in 1974. Hide Caption 3 of 43 Photos: Hillary Clinton's life in the spotlight In 1975, Rodham married Bill Clinton, whom she met at Yale Law School. He became the governor of Arkansas in 1978. In 1980, the couple had a daughter, Chelsea. Hide Caption 4 of 43 Photos: Hillary Clinton's life in the spotlight Arkansas' first lady, now using the name Hillary Rodham Clinton, wears her inaugural ball gown in 1985. Hide Caption 5 of 43 Photos: Hillary Clinton's life in the spotlight The Clintons celebrate Bill's inauguration in Little Rock, Arkansas, in 1991. He was governor from 1983 to 1992, when he was elected President. Hide Caption 6 of 43 Photos: Hillary Clinton's life in the spotlight Bill Clinton comforts his wife on the set of "60 Minutes" after a stage light broke loose from the ceiling and knocked her down in January 1992. Hide Caption 7 of 43 Photos: Hillary Clinton's life in the spotlight In June 1992, Clinton uses a sewing machine designed to eliminate back and wrist strain. She had just given a speech at a convention of the International Ladies' Garment Workers Union. Hide Caption 8 of 43 Photos: Hillary Clinton's life in the spotlight During the 1992 presidential campaign, Clinton jokes with her husband's running mate, Al Gore, and Gore's wife, Tipper, aboard a campaign bus. Hide Caption 9 of 43 Photos: Hillary Clinton's life in the spotlight Clinton accompanies her husband as he takes the oath of office in January 1993. Hide Caption 10 of 43 Photos: Hillary Clinton's life in the spotlight The Clintons share a laugh on Capitol Hill in 1993. Hide Caption 11 of 43 Photos: Hillary Clinton's life in the spotlight Clinton unveils the renovated Blue Room of the White House in 1995. Hide Caption 12 of 43 Photos: Hillary Clinton's life in the spotlight Clinton waves to the media in January 1996 as she arrives for an appearance before a grand jury in Washington. The first lady was subpoenaed to testify as a witness in the investigation of the Whitewater land deal in Arkansas. The Clintons' business investment was investigated, but ultimately they were cleared of any wrongdoing. Hide Caption 13 of 43 Photos: Hillary Clinton's life in the spotlight The Clintons hug as Bill is sworn in for a second term as President. Hide Caption 14 of 43 Photos: Hillary Clinton's life in the spotlight The first lady holds up a Grammy Award, which she won for her audiobook "It Takes a Village" in 1997. Hide Caption 15 of 43 Photos: Hillary Clinton's life in the spotlight The Clintons dance on a beach in the U.S. Virgin Islands in January 1998. Later that month, Bill Clinton was accused of having a sexual relationship with former White House intern Monica Lewinsky. Hide Caption 16 of 43 Photos: Hillary Clinton's life in the spotlight Clinton looks on as her husband discusses the Monica Lewinsky scandal in the Roosevelt Room of the White House on January 26, 1998. Clinton declared, "I did not have sexual relations with that woman." In August of that year, Clinton testified before a grand jury and admitted to having "inappropriate intimate contact" with Lewinsky, but he said it did not constitute sexual relations because they had not had intercourse. He was impeached in December on charges of perjury and obstruction of justice. Hide Caption 17 of 43 Photos: Hillary Clinton's life in the spotlight The first family walks with their dog, Buddy, as they leave the White House for a vacation in August 1998. Hide Caption 18 of 43 Photos: Hillary Clinton's life in the spotlight President Clinton makes a statement at the White House in December 1998, thanking members of Congress who voted against his impeachment. The Senate trial ended with an acquittal in February 1999. Hide Caption 19 of 43 Photos: Hillary Clinton's life in the spotlight Clinton announces in February 2000 that she will seek the U.S. Senate seat in New York. She was elected later that year. Hide Caption 20 of 43 Photos: Hillary Clinton's life in the spotlight Clinton makes her first appearance on the Senate Environment and Natural Resources Committee. Hide Caption 21 of 43 Photos: Hillary Clinton's life in the spotlight Sen. Clinton comforts Maren Sarkarat, a woman who lost her husband in the September 11 terrorist attacks, during a ground-zero memorial in October 2001. Hide Caption 22 of 43 Photos: Hillary Clinton's life in the spotlight Clinton holds up her book "Living History" before a signing in Auburn Hills, Michigan, in 2003. Hide Caption 23 of 43 Photos: Hillary Clinton's life in the spotlight Clinton and another presidential hopeful, U.S. Sen. Barack Obama, applaud at the start of a Democratic debate in 2007. Hide Caption 24 of 43 Photos: Hillary Clinton's life in the spotlight Obama and Clinton talk on the plane on their way to a rally in Unity, New Hampshire, in June 2008. She had recently ended her presidential campaign and endorsed Obama. Hide Caption 25 of 43 Photos: Hillary Clinton's life in the spotlight Obama is flanked by Clinton and Vice President-elect Joe Biden at a news conference in Chicago in December 2008. He had designated Clinton to be his secretary of state. Hide Caption 26 of 43 Photos: Hillary Clinton's life in the spotlight Clinton, as secretary of state, greets Russian Prime Minister Vladimir Putin during a meeting just outside Moscow in March 2010. Hide Caption 27 of 43 Photos: Hillary Clinton's life in the spotlight The Clintons pose on the day of Chelsea's wedding to Marc Mezvinsky in July 2010. Hide Caption 28 of 43 Photos: Hillary Clinton's life in the spotlight In this photo provided by the White House, Obama, Clinton, Biden and other members of the national security team receive an update on the mission against Osama bin Laden in May 2011. Hide Caption 29 of 43 Photos: Hillary Clinton's life in the spotlight Clinton checks her Blackberry inside a military plane after leaving Malta in October 2011. In 2015, The New York Times reported that Clinton exclusively used a personal email account during her time as secretary of state. The account, fed through its own server, raises security and preservation concerns. Clinton later said she used a private domain out of "convenience," but admits in retrospect "it would have been better" to use multiple emails. Hide Caption 30 of 43 Photos: Hillary Clinton's life in the spotlight Clinton arrives for a group photo before a forum with the Gulf Cooperation Council in March 2012. The forum was held in Riyadh, Saudi Arabia. Hide Caption 31 of 43 Photos: Hillary Clinton's life in the spotlight Obama and Clinton bow during the transfer-of-remains ceremony marking the return of four Americans, including U.S. Ambassador Christopher Stevens, who were killed in Benghazi, Libya, in September 2012. Hide Caption 32 of 43 Photos: Hillary Clinton's life in the spotlight Clinton ducks after a woman threw a shoe at her while she was delivering remarks at a recycling trade conference in Las Vegas in 2014. Hide Caption 33 of 43 Photos: Hillary Clinton's life in the spotlight Clinton, now running for President again, performs with Jimmy Fallon during a "Tonight Show" skit in September 2015. Hide Caption 34 of 43 Photos: Hillary Clinton's life in the spotlight Clinton testifies about the Benghazi attack during a House committee meeting in October 2015. "I would imagine I have thought more about what happened than all of you put together," she said during the 11-hour hearing. "I have lost more sleep than all of you put together. I have been wracking my brain about what more could have been done or should have been done." Months earlier, Clinton had acknowledged a "systemic breakdown" as cited by an Accountability Review Board, and she said that her department was taking additional steps to increase security at U.S. diplomatic facilities. Hide Caption 35 of 43 Photos: Hillary Clinton's life in the spotlight U.S. Sen. Bernie Sanders shares a lighthearted moment with Clinton during a Democratic presidential debate in October 2015. It came after Sanders gave his take on the Clinton email scandal. "The American people are sick and tired of hearing about the damn emails," Sanders said. "Enough of the emails. Let's talk about the real issues facing the United States of America." Hide Caption 36 of 43 Photos: Hillary Clinton's life in the spotlight Clinton is reflected in a teleprompter during a campaign rally in Alexandria, Virginia, in October 2015. Hide Caption 37 of 43 Photos: Hillary Clinton's life in the spotlight Clinton walks on her stage with her family after winning the New York primary in April. Hide Caption 38 of 43 Photos: Hillary Clinton's life in the spotlight After Clinton became the Democratic Party's presumptive nominee, this photo was posted to her official Twitter account. "To every little girl who dreams big: Yes, you can be anything you want -- even president," Clinton said. "Tonight is for you." Hide Caption 39 of 43 Photos: Hillary Clinton's life in the spotlight Obama hugs Clinton after he gave a speech at the Democratic National Convention in Philadelphia. The president said Clinton was ready to be commander in chief. "For four years, I had a front-row seat to her intelligence, her judgment and her discipline," he said, referring to her stint as his secretary of state. Hide Caption 40 of 43 Photos: Hillary Clinton's life in the spotlight Clinton arrives at a 9/11 commemoration ceremony in New York on September 11. Clinton, who was diagnosed with pneumonia two days before, left early after feeling ill. A video appeared to show her stumble as Secret Service agents helped her into a van. Hide Caption 41 of 43 Photos: Hillary Clinton's life in the spotlight Clinton addresses a campaign rally in Cleveland on November 6, two days before Election Day. She went on to lose Ohio -- and the election -- to her Republican opponent, Donald Trump. Hide Caption 42 of 43 Photos: Hillary Clinton's life in the spotlight After conceding the presidency to Trump in a phone call earlier, Clinton addresses supporters and campaign workers in New York on Wednesday, November 9. Her defeat marked a stunning end to a campaign that appeared poised to make her the first woman elected US president. Hide Caption 43 of 43

First, Clinton experienced warning symptoms, namely the sensation of overheating (and perhaps other symptoms her team hasn't supplied), which prompted her to decide to leave an outdoor event in the summer sun after she'd attended for about 90 minutes. Each of these facts is crucial.

The most important job doctors face when evaluating a brief fainting spell is figuring out whether the heart is involved. Did the heart skip into a bad rhythm, one that wasn't able to get enough blood supply to the brain? If that happens, in most cases, the event is sudden and with no warning, unlike in Clinton's case. In such situations the person also rebounds fairly suddenly. They don't need a rest and recovery period to gradually return to baseline like Clinton did.

Clinton's gradual onset of symptoms also come in the context of her attending an outdoor event for an extended period that involved a lot of standing. This is key medical history that points to a blood pressure drop, and the most common cause of that is a so-called vasovagal episode.

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In typical vasovagal syncope, there's less blood in the upper body when you're standing because it's pooling in the lower body, and maybe you're dehydrated to boot. Your heart tries to forcefully contract to make up for the lack of sufficient blood in its chambers, so much so that it overstimulates itself into activating an arm of the nervous system that's normally responsible for bringing down the heart rate and blood pressure (the parasympathetic nervous system, which connects to the heart through the vagus nerve - the "vagal" in vasovagal).

Prolonged standing is just one of many common causes of vasovagal syncope, another is overheating, which also dilates blood vessels and drops blood pressure. While the New York air itself wasn't particularly hot Sunday morning (lower 80s), the air temperature doesn't dictate your surface temperature in the sun, which can still send plenty of heat into your body and clothing (especially if dark like Clinton's outfit). Anyone who's enjoyed Southern California's wonderful weather has experienced this phenomenon.

Beyond the pneumonia, I also suspect that Clinton's allergies, which her doctor described in her medical attestation last year and which we've all heard about thanks to the candidate's periodic coughing fits, played a role. Coughing, whether due to pneumonia or allergies, can itself kick off a reflexive surge in the parasympathetic nervous system that drops the blood pressure and causes you to faint.

In short, if Clinton came into an emergency room with this history, most ER doctors wouldn't see the need to refer her for advanced testing.

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But of significant concern to me is that Clinton told reporters Tuesday that she "just upped my antihistamine load to try to break through" her latest allergy exacerbation.

Antihistamines need to be used in moderation. The potential side effects are broad, they're a brute weapon in the battle against allergies because they interplay with the nervous system. The drug class is well known to play a role in fainting spells, and if Clinton just increased her dose this week, that's a factor her doctor should consider in her future allergy management.

But what about Clinton's history of a concussion and a blood clot in her brain in late 2012 (cerebral venous sinus thrombosis)? This piece of medical history is of the greatest interest to Clinton's health conspiracy theorists, but it's the least likely factor in her near fainting spell Sunday.

Because of prior blood clots in her legs, and the one that occurred in a brain blood vessel, her doctor decided to start her on the blood thinner warfarin, and she's taking that chronically. Video shows Clinton emerging from her daughter's apartment having recovered fairly quickly. If another cerebral venous thrombosis or other brain circulation issue had occurred, she wouldn't be back in business so quickly.

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Respiratory infections that progress to the lung, i.e. pneumonia, are exceedingly common, particularly in older adults like Clinton. They are among the normal medical events in anyone's life, and both pneumonia and a fainting spell both will feature strongly in the average lifespan. That said, bugs causing pneumonia are more serious than others, and may point to other underlying conditions.

I would like to see the Federal Election Commission regularly convene panels of independent physicians to review the chief executive candidate's medical records in fine detail. Such a panel would then issue a believable third-party check (more important for some candidates' doctors than others).

Such a review could benefit the candidates as well as the nation: Sometimes it helps to have more than one medical set of eyes. There are successful companies dedicated to the concept of second and third opinions, and our chief executive deserves to benefit from that level of care.

You needn't be the picture of health to serve as President of the United States, but even if you are, you're never above an infection or a fainting spell.