"I have instructed my long-term doctor to issue, within two weeks, a full medical report-it will show perfection," Trump tweeted. | Getty Trump doctor: I wrote health letter in 5 minutes

The famous letter proclaiming that Donald Trump would be the healthiest president ever was written in just five minutes, Trump’s personal doctor said on Friday.

Dr. Harold Bornstein dashed off the letter in December while a limo sent by Trump waited outside his office to collect the document, he told NBC News. The letter said he had been Trump's personal physician since 1980.


"If elected, Mr. Trump, I can state unequivocally, will be the healthiest individual elected to the presidency," reads the letter, which is dated Dec. 4, 2015, and was released by the Trump campaign days later. The letter also says that Trump's blood pressure and lab results were "astonishingly excellent" and that "[h]is physical strength and stamina are extraordinary."

In his NBC interview Friday, Bornstein stood by that assessment.

"His health is excellent, especially his mental health. He thinks he's the best, which works out just fine," he said.

He added, "I think he would be fit because, I think his brain is turned on 24 hours a day."

Bornstein is a gastroenterologist based at Lenox Hill Hospital on Manhattan's Upper East Side, about a mile from Trump Tower. He is a certified member of the American Board of Internal Medicine, according to his website, which does not list a license to practice psychology or psychiatry.

Ten days before the letter's release, Trump tweeted, "I have instructed my long-term doctor to issue, within two weeks, a full medical report-it will show perfection."

But the letter, just 14 sentences long, hardly constitutes a "full medical report" of the kind that past presidential nominees have released. It also contains several errors: It begins "To Whom My Concerns," and says that Bornstein's most recent medical examination of Trump "showed only positive results" -- medical terminology that usually indicates confirmation of a certain condition.

Bornstein explained that he didn’t have time to write the letter until the limo was arriving at his office, and didn’t proofread it before he sent it off.

"I thought about it all day and at the end, I get rushed and I get anxious when I get rushed. So I try to get four or five lines down as fast as possible so that they would be happy," he told NBC News.

As for the letter's purple, Trump-like prose, "I think I picked up his kind of language and then just interpreted it to my own," he said.

But, he added, "In the rush, I think some of those words didn't come out exactly the way they were meant."

Bornstein, according to NBC News, didn’t go in-depth on his political views, but did say, “I like Donald Trump because I think he likes me.” According to voter records, he was a registered Republican in the past but is currently not registered with the party.

In recent days, the 70-year-old Trump has intensified his attacks on Hillary Clinton’s health, saying he has doubts about her ability to serve as president. Clinton, who is 68, and her team have pushed back forcefully, dismissing the speculation from Trump surrogates such as Fox News host Sean Hannity as "lies and deranged conspiracy theories." But Clinton has likewise declined to share her full medical records; she released a somewhat lengthier letter from her doctor in July 2015.

POLITICO has tried contacting Bornstein in the past, but he has deferred to the campaign, which has declined to comment.