Hillary Clinton’s campaign has acknowledged mishandling news of her pneumonia, as Donald Trump sought to capitalize on growing questions over his opponent’s trustworthiness at a critical moment in their race for the White House.

“We could have done better yesterday,” wrote Clinton communications director Jennifer Palmieri on Monday, after some Democrats began questioning whether the campaign had been fully transparent in its weekend accounts of her health.

On Monday evening, the Democratic presidential candidate phoned in to CNN, telling host Anderson Cooper that she hadn’t initially thought her pneumonia “was a big deal”. She also tweeted her thanks to well-wishers and added:

Like anyone who’s ever been home sick from work, I’m just anxious to get back out there. See you on the trail soon. -H — Hillary Clinton (@HillaryClinton) September 12, 2016

She went on to send two tweets attacking Trump.

Clinton was filmed losing her footing and being assisted into a waiting van after leaving early from a memorial for 9/11 victims in New York on Sunday.

Initially, campaign aides said she had “overheated”, though Clinton later insisted “I’m feeling great, it’s a beautiful day in New York,” after she left her daughter’s apartment, where she had been taken to rest.

But once the video footage emerged – which appeared to support witness accounts of a more serious incident – the campaign issued a short statement from a doctor revealing she was being treated for pneumonia.

A sign along a road near Hillary Clinton’s home on Monday in Chappaqua, New York. Photograph: Don Emmert/AFP/Getty Images

Clinton had been diagnosed on Friday but the condition went undisclosed despite the campaign chastising reporters who had questioned bouts of coughing at recent public events.

“In retrospect, we could have handled it better in providing more information. That’s on us. We regret that,” said press secretary Brian Fallon.

The campaign now says Clinton will release “additional medical information” from her doctor in the next few days “to further put to rest any lingering concerns”, but insists there are “no other underlying conditions, the pneumonia is the extent of it”.



“I expect by the middle or back end of the week she will be back out there on the campaign trail,” Fallon told MSNBC. “If it was up to her she would be travelling to California today but it was her doctor’s advice [to rest at home].”

Clinton added in the phone interview withCNN’s Anderson Cooper that she didn’t initially reveal the pneumonia diagnosis because she “didn’t think it was a big deal”. However after the incident on Sunday, where she insisted that she did not faint, the former secretary of state was now following her initial doctor’s advice to take five days of rest in order to fully recover.

However, even if Clinton does bounce back quickly, the incident is raising fresh questions over trust which could cause more lingering political complications.

“Antibiotics can take care of pneumonia. What’s the cure for an unhealthy penchant for privacy that repeatedly creates unnecessary problems?” wrote Barack Obama’s former adviser David Axelrod.

His tweet prompted Palmieri’s first acknowledgement of regret, in which she added: “But it is a fact that [the] public knows more about HRC than any nominee in history.”

Their public exchange was seized on by the Trump campaign, which said it demonstrated a familiar pattern of secrecy by the Clintons.

“It’s incredibly important to be forthcoming,” said the Republican’s campaign manager, Kellyanne Conway. “If you have a diagnosis of pneumonia, just be honest about it when you’re saying you’re overheating. Just say, ‘By the way, I’m on antibiotics’.”

Trump claimed he would soon be releasing the results of a recent physical examination of his own, telling interviewers: “It’s interesting because they say pneumonia, but she was coughing very, very badly a week ago … It’s very interesting to see what’s going on.”

Clinton’s campaign and its backers nonetheless pushed back against criticism regarding transparency. Trump, they pointed out, had thus far declined to release his tax returns and refused to offer policy specifics on issues ranging from immigration to the fight against Islamic State. As Clinton herself argued on Monday: “We know the least about Donald Trump than any candidate in recent American history.”

The state of Trump’s own health was also unclear, with a brief statement from his personal doctor of 25 years in December providing few medical details and serving as the only record offered by his campaign.

The doctor’s statement described the Republican nominee in the sort of hyperbolic language typically associated with Trump, declaring him “the healthiest individual ever elected to the presidency” if successful in his pursuit of the White House. Trump’s physician, Dr Harold Bornstein, said last month he put the document together in five minutes while awaiting a limo sent by Trump to collect the letter. Clinton described this letter in her CNN interview as “not even serious”.

Despite repeatedly criticizing Clinton’s “stamina” in recent weeks, Trump was cautious on the topic of the former secretary of state’s health on Monday, saying in an interview: “I hope she gets well soon.”

Trump instead focused his fire on Clinton’s comments on Friday about half of Trump’s voters being in “the basket of deplorables”. Although she has since expressed regret for being “grossly generalistic” in saying “half”, she still stood by her characterization of some Trump supporters. Clinton has continued to reiterate: “Trump has built his campaign largely on prejudice and paranoia and given a national platform to hateful views and voices.”

The Trump campaign has seized on these remarks and is now airing a television ad highlighting them in several swing states. The ad includes footage of Clinton grouping “the racists, sexists, homophobic, xenophobic, Islamophobic, you name it” into the “basket of deplorables”.

The stumbles for Clinton come as polls appear to show Trump reducing a previously large gap, to an average of three points.

Even as her campaign sought to rein in any political damage from the past few days, several Democrats argued that the focus on Clinton’s health had been overblown by the media.

“Every candidate I have ever worked for has gotten sick on the trail and worked through it because you can’t take days off in a close race,” wrote Dan Pfeiffer, a former senior adviser to Obama.

Bill Burton, who served as Obama’s national press secretary in 2008, said campaign aides would have been “understandably skittish about making announcements about secretary Clinton’s health” while Trump was pushing conspiracy theories about her wellbeing.

“Will it feed a narrative? Sure,” he said in an interview. “But only because the media gets led around by the nose by Donald Trump.”

And while the media was quick to cast the incident as problematic for Clinton, Burton said it could in fact provide her with a small boost in the polls.

“People respond when they think someone’s being treated unfairly,” he said.

“For Hillary Clinton to have pneumonia and even still give a press conference, convene a national security meeting, attend a memorial service in the hot sun for an hour and a half, and then take criticism for having pneumonia all the while … I don’t think the American people are going to punish her for actually performing quite well in the face of what’s an exhausting illness.”