Sean Hannity, host of "Hannity" on Fox News. (Carolyn Kaster/AP)

Every night this week, Fox News' Sean Hannity has drawn attention to a story that was largely debunked before Monday morning. Again and again, Hannity has summoned a "Fox News Medical A-Team" to probe the claim that Hillary Clinton has serious medical issues, covered up by a press that won't demand her medical records.

Hannity's crusade has given the theories of a looming Clinton health crisis their highest-profile airing. A year ago, when Republicans hoped that one of several younger candidates would win their nomination, jokes about Clinton's age and health were rampant. Senate Majority Leader Mitch McConnell (R-Ky.) said at the Conservative Political Action Conference that the Democratic nomination fight looked like "an episode of 'Golden Girls.'" The Washington Free Beacon ran jokey investigations of a photo that showed Clinton holding the back of a chair, asking whether she was using a walker. (She was not.)

But in the last week, the baseless allegations of secret Clinton health issues have heated up on fringe news sites, and Hannity has booked doctors to discuss them on his eponymous news show, one of cable's highest-rated. On Monday, Hannity informed his viewers that a photo "which shows Hillary Clinton apparently needing assistance to climb a flight of stairs at a campaign stop back in February" went viral thanks to a prominent link on the Drudge Report. Hannity did not note, as the photo service Getty Images noted, that Clinton had merely stumbled and been caught by Secret Service agents. Instead, he told viewers that the Clinton campaign refused to comment on the new attention paid to the photo, apart from criticizing the source.

"What was noticeably missing from the statement is any reference or rebuttal to the health issues that were alleged by Drudge and others," Hannity said.

He brought in Marc Siegel and David Samadi, two Fox News medical pundits who had never examined Clinton personally, but who suggested that the photo, Clinton's 2012 concussion and three falls since the start of the Obama administration raised serious questions.

"You see from our picture up there that it looks like she can barely get up stairs without two people carrying her," Siegel said. "I want to know what her neurologist says. I've reached out to her neurologist at Columbia after she had that fall. No comment. I want to know what her neurological records show."

Samadi, a urologist, argued that the picture of Clinton's stumble spoke "a million words" about her health. "Is she really fatigued?" he asked. "Is she dehydrated? One of the main reasons why she fell in 2012 and had the concussion was severe dehydration. They're holding her and going up the stairs so she may be really dehydrated, she may have arthritis, she may have back pain. She may have fallen again. We don't know."

In fact, Clinton completed a campaign visit after the stumble pictured in the February photo. But Hannity brought another fishy analysis into the conversation by asking if a viral photo of Clinton and Secret Service agent Todd Madison revealed a diazepam pen, used to treat seizures.

"What about this photo that the Gateway Pundit had up today?" Hannity asked. "Hillary's handler gets caught with a diazepam pen. What would that be for?"

"Someone is carrying a pen that you'd use in case of a seizure, a Valium pen — that makes me wonder about that," Siegel said.

In fact, as the fact-checking site Snopes later uncovered, the agent was holding what appeared to be a small flashlight; the rumor that he was holding a medical device was based entirely on hearsay.

But by Tuesday night, Hannity had moved on to another flimsy theory of Clinton's health. Keying off short clips of Clinton pausing over words, Hannity speculated that her 2012 concussion had caused long-term damage.

"What about some of the weird pauses she has, the coughing fits she has?" he asked Siegel, appearing for the second night. "There are moments when I'm literally watching her and I'm thinking, okay, the facial expressions are odd. They seem off."

At first, Siegel restrained himself. "I don't know this because I'm only looking at a video," he said. "But I saw the same video you saw, and I'm wondering about a word called 'aphasia,' where you're searching for words, you suddenly lose those words, and that can be the sign, again, of some kind of traumatic brain injury or the aftereffects of a concussion."

Daniel Kassicieh, a Florida-based neurologist, joined the panel to agree that Clinton's medical records needed to be released. "I'm very concerned about the long-term latent effects of the concussion that show up as things such as memory loss, forgetfulness, difficulty concentrating, things such as that video that showed her pausing for a very long time as though she were searching for the right words, losing track of what you're thinking about," he said.

Little had been advanced by the panel, but on Wednesday, Hannity invited Siegel back and added New Jersey neurologist Fiona Gupta. He played back the clips that had been circulated the most by online conspiracy theorists, including two videos of Clinton coughing ("Those coughing fits go on for a long period of time") and one of her making an exaggerated bobble-head motion when reporters ask her questions in a scrum.

"That last one is so odd to me," Hannity said.

"It's just so hard to speculate based on snippets," said Gupta.

"But watch this video," said Hannity, playing back the bobble-head clip. "It almost seems seizure-esque to me."

"I mean, there are types of series, like focal seizures, that sometimes can cause just one body part [to seize]," said Gupta. "It could be the stress."

"But aren't there many seizures like that?" Hannity asked.

"I'm not a neurologist, and I don't think that necessarily looks like a seizure," Siegel said.

"Well, then, what would that be?" Hannity asked, having the clip played again as Siegel answered.

"I think we're seeing enough there, especially in someone who has a long medical history, and who's approaching 70 years old, for me to say that both candidates need to release their medical records," Siegel said.

(Clinton has so far released a letter from her physician that says she had a concussion in 2012 and has hypothyroidism now.)

"But it looks like violent, out-of-control movements on her part," Hannity said.

"And it could be — I said, could be — related to previous medical trauma she's had," said Siegel, pivoting once more to the need for both Clinton and Donald Trump to be transparent.

One of the latest conspiracy theories targeting Clinton is that the medical records have been found and are being released by a whistleblower; the "leaked" documents lack the formatting and letterhead used by Clinton's physician and get the doctor's title wrong.

Donald Trump appeared at a town hall event on Fox News on April 4 – but it felt a lot more like a rally than a question-and-answer session. (Peter Stevenson/The Washington Post)