Democratic presidential candidate Hillary Clinton gets into a van as she leaves an apartment building Sunday, Sept. 11, 2016, in New York. (AP Photo/Andrew Harnik)

Before Sunday morning, the conspiracy theories collected under the hashtag #HillarysHealth were numerous.

According to Sean Hannity's "medical A-team," the Democratic nominee was wracked by seizures. According to Ted Noel, an anesthesiologist with no expertise in Parkinson's disease, Clinton had Parkinson's disease. According to Gateway Pundit and InfoWars, both sites linked regularly by The Drudge Report, Clinton was followed by a medical "mystery man" and might well have used a secret earpiece to get answers fed to her at the "Commander in chief" forum. The Drudge Report itself had promoted an Internet poll conducted by the Association of American Physicians and Surgeons — a fringe group that questions whether HIV causes AIDS — as proof that doctors were coalescing around the theory of the candidate's declining health.

On those counts, Sunday was a debacle — a reversal of the story line that Clinton was concealing permanent neurological damage. For a few hours, Clinton's stagger toward the van that took her to her daughter's New York apartment was interpreted as proof that the worst conspiracy theories had been right — and just as importantly, that the media had covered them up.

"The most likely diagnosis — in my mind — an acute cardiac arrhythmia — either ventricular tachycardia — or more likely atrial fibrillation with a rapid ventricular response," wrote a reader to American Conservative columnist Rod Dreher.

"Sick Hillary's cough is caused by Parkinson's disease," wrote self-published author Mike Cernovich.

Then came the Clinton campaign's belated admission that the candidate was being treated for pneumonia. The operating theory among skeptics had been that Clinton was covering up permanent, degenerative medical issues; the new diagnosis contradicted that, presenting a candidate who had tried and failed to push through an illness.

But as is the custom in the "undernews," the new information was absorbed into the greater theory. In the very short term, #HillarysHealth sleuths celebrated the frustration of Clinton beat reporters who, after days of knocking down conspiracy theories, were venting about the campaign's attempt to cover up the pneumonia.

"The whole issue of transparency and this only reinforces all of the conspiracy theories, ” said MSNBC's Andrea Mitchell, in remarks turned into a quick reaction story on InfoWars. “I mean, we’ve all been trying to fact-check and pointing out that there’s nothing wrong with her."

The Clinton campaign's fumbling of the news led to a series of similar analyses — all of them taking for granted that any Clinton misstep would encourage conspiracy theorists.

"The truth, of course, is that pneumonia is not dysphasia," wrote the Economist. "Yet millions of Americans, livid with Mrs. Clinton and the establishment politics she represents, might just consider that to be splitting hairs."

At the same time, the well-documented Clinton collapse at the 9/11 memorial was spawning new theories, without regard to the defunct ones. For more than a month, the sleuths had insisted that Todd Madison, a Secret Service agent who travels with Clinton, was a mysterious doctor who was supplying her with meds. (As late as last week, the Drudge Report linked to a report insisting that no one knew who Madison was with the headline "Who is he?") In the viral video of Clinton staggering to her waiting van, Madison opened the door; other agents largely helped her in.

That was accounted for, as #HillarysHealth sleuths focused on a new member of the Clinton entourage — a brunette women seen holding the Democratic nominee's hand in photos from the memorial.

Clinton campaign spokesman Brian Fallon identified the woman holding Clinton's hand as Christine Falvo, a former Senate staffer, and not a secret new physician. And Fallon pronounced "absurd" another blossoming theory — that Clinton had let a body double take her place. Throughout Monday, the hashtag #HillarysBodyDouble ticked up, thanks both to credulous tweets and parodies of the theory from sites like Cafe.

But most of the tweets were genuine, sharing images meant to demonstrate that Clinton looked so different from photo to photo that she must have been replaced.

https://twitter.com/trump2016fan/status/775309732391235584

https://twitter.com/American1765/status/775296484216442880

As the "body double" theory trended, Clinton impersonator Teresa Barnwell noticed her appearance in Reddit threads and investigative tweets. As she first told The Daily Beast, she played along, tweeting a (now-deleted) photo of herself at Chelsea Clinton's apartment.

Within hours, she tried to tamp down the theories by confirming that she was in Los Angeles, shooting a lip sync contest with a Bill Clinton impersonator.

Early on Monday morning, Barnwell tried to be clearer — learning, the hard way, about the tenacity of Clinton conspiracy theorists.