Since she was abruptly whisked away from a 9/11 service at ground zero in Manhattan over the weekend, Clinton has seen her polling lead over Donald Trump tighten significantly and almost vanish.
The Hillary Clinton campaign has released updated health information for the Democratic presidential candidate.
Clinton was forced to leave ceremonies marking the annivary of the September 11 attacks in NY on Sunday because of a dizzy spell.
The rest of the physical exam "was normal and she is in excellent mental condition", Bardarck said in a letter to the media, saying that she examined Clinton several times this week.
The US Secretary of State John Kerry has told Sky News he is "absolutely convinced" Hillary Clinton is up to being president after her health scare.
At a rally in OH on Wednesday, Mr Trump used Mrs Clinton's recent health scare to cast doubt on her stamina.
"Health is an important issue for any candidate, but it's especially true with two candidates who would be governing in their 70s", David Gergen, who worked in Bill Clinton's White House and has served three Republican presidents, told The Wall Street Journal. Neither has any known major medical problems.
Following the revelation of Clinton's pneumonia, Trump vowed soon to release "very, very specific numbers" from a recent check-up with Bornstein.
Meanwhile, her rival Donald Trump has also announced the release the details of his recent physical tes this week.
Highlights From the 2016 Campaign Trail Drew Angerer Getty Images
Mr Trump discussed the results of his physical ahead of the airing of a taped interview with TV personality Dr Oz.
Trump produced it unexpectedly during the recording of the show on Wednesday, after his campaign had said he wouldn't, and he gave it to the host, who was seen taking a long look at it in promotional clips. "I don't care. Should I do it?"
A vast majority of Clinton and Trump supporters said their mind is set.
Bardack is the chair of internal medicine at CareMount Medical in Mount Kisco, New York, and has served as Clinton's personal physician since 2001. The letter detailed her pneumonia diagnosis and declared her fit for the presidency.
Clinton, 68, has blood pressure of 100 over 70 - within healthy levels and not signaling the need for any medications.
The Democratic presidential candidate faces increased scrutiny about her health after a video showed her staggering while getting into a van on Sunday.
"For millions of moms and dads, if they get sick there is no backup, they are on their own", she said.
The physician said Mrs Clinton was up to date on all vaccines, including two given to help prevent pneumonia, Prevnar and Pneumovax.
Speaking to reporters, Clinton was more defensive. She was tested with a noncontrast chest CT scan, which discovered a small right middle-lobe pneumonia.