White House press secretary Sarah Huckabee Sanders said Thursday that Jackson will issue a "brief statement" after the physical, then will compile detailed results over the long weekend and appear at Tuesday's press briefing to take questions.
"I think it's going to go very well," Trump said on Thursday afternoon. "I'll be very surprised if it doesn't."
Undergoing this physical is voluntary, and Trump can pick and choose what the public hears about his health.
Sanders announced the exam in early December, a day after the president gave a speech announcing his plans to recognise Jerusalem as Israel's capital and, at one point, heavily slurred his words. At the time, Sanders said that the president's throat was simply dry, and she said this week that the exam had been in the works before that incident.
The exam will not include a psychological test, a White House spokesman said, and officials would not say whether Trump will undergo cognitive tests. Trump's mental fitness has come under scrutiny after the release of a book that portrayed him as unprepared for the presidency, incapable of processing information and uninterested in making difficult decisions.
The physical-exam results disclosed by previous presidents have varied. Obama, George W. Bush and Bill Clinton all released their heights and weights, lists of the medications they took, cholesterol levels, blood pressure and other lab results.
Obama's reports were usually two pages with details about his on-again-off-again relationship with smoking ("smoking cessation efforts" in 2010, "tobacco free" in 2011 and "remains tobacco free" in 2014 and 2016). Bush's results often filled more than four pages, even disclosing his body-fat percentage. Clinton's doctor acknowledged his struggles to stay healthy amid the stress of the presidency and campaigning, and the 6-foot-2 president weighed 214 pounds at his last exam in 2001.
Trump said in 2016 that he is 6-foot-3 and 236 pounds, which the medical community considers overweight; if he was 6-foot-2, as listed on his New York driver's license, he would be considered obese. At the time, Trump acknowledged that he needed to lose 15 to 20 pounds. Since his inauguration, Trump appears to have gained weight.
The Friday exam could reveal great insight into Trump's health - or at least provide a verified assessment of his height and weight. During the campaign, Trump released two one-page letters from his personal physician in New York, Harold N. Bornstein, that showed his cholesterol levels were controlled with medication and were within the healthy range for a man his age. At the time, Trump's blood pressure was 116/70, and his blood sugar was 99, both of which are normal. Bornstein said a series of other tests - an EKG and chest x-ray in April 2016, a transthoracic echocardiogram, or ultrasound of the heart, in December 2014 and a colonoscopy in July 2013 - were all normal.
Bornstein's statement said that Trump has been "hospitalised" only once, for an appendectomy when he was 11 years old. In a December 2015 letter - the one in which he proclaimed Trump would "be the healthiest individual ever elected to the presidency" - Bornstein wrote that the appendectomy was Trump's "only surgery." Ivana Trump, the president's first wife, testified in a sworn deposition during their divorce proceedings in the early 1990s that Trump also had scalp reduction surgery, which Trump has denied.
Bornstein wrote that Trump takes just two medications: a small dose of aspirin and a statin to lower his cholesterol. Bornstein said in an interview with the New York Times last year that Trump had also taken a prostate-related drug that can promote hair growth and an antibiotic to control rosacea, a common skin problem.
In discussing his health, Trump usually points to the longevity of his parents: His mother was 88 when she died, and his father died at 93 after suffering from Alzheimer's disease for about five years.
"I consider my health, stamina and strength one of my greatest assets," Trump tweeted in December 2015. "The world has watched me for many years and can so testify - great genes!"
Trump has other factors working in his favor: He grew up in a wealthy family and had access to quality health care. He says he has never drank alcohol or smoked. And he minimises his access to germs, even avoiding handshakes.
"It's a medical fact that this is how germs are spread," Trump wrote in his 2004 book, "How to Get Rich." "I wish we could follow the Japanese custom of bowing instead."
Trump answered questions about his health during a September 2016 interview with the television personality Mehmet Oz. Trump said he had not been sick in years - "People are amazed because I don't get much with the colds" - and feels like he is still 35 years old. Trump said that his primary form of exercise at the time was giving rally speeches.
"I'm up there using a lot of motion - I guess in it's own way, it's a pretty healthy act," Trump said. "A lot of times, these rooms are very hot, like saunas, and I guess that is a form of exercise."
Since the election, Trump has golfed several times a month, although he rides in a golf cart as much as possible. During a photo shoot with fellow world leaders in Italy last summer, Trump was transported in a golf cart up a small hill while everyone else walked.
The president once explained that he believes "the human body was like a battery, with a finite amount of energy, which exercise only depleted" - a theory refuted by doctors and physical trainers.
Later in the interview, Trump said he had long struggled with his weight and hoped to lose 15 or 20 pounds, although "it's tough because of the way I live." A recent book by former campaign manager Corey Lewandowski and former aide David Bossie, "Let Trump be Trump," said the presidential candidate would often eat one McDonald's meal a day consisting of two Big Macs, two Filet-O-Fish sandwiches and a chocolate shake - a menu that would total 2,430 calories and more than 3,400 milligrams of sodium.
Heavy bursts of fast food are not part of most doctor-recommended eating plans. During the filming of "Super Size Me," Isaacs said the documentary's protagonist gained 24 pounds in a month, had increased cholesterol and other health problems and quickly developed "fatty liver" because the organ could not handle the consumption of a heavily caloric meal in a short period of time.
Medical experts interviewed by The Washington Post were reluctant to comment specifically about President Trump because they do not have access to all the relevant information about his health profile. But all said the diet and exercise regimen he has acknowledged following diverges widely from the guidelines they provide their patients.
That includes a diet heavy in fruits, vegetables and low-fat protein such as chicken and fish, with small amounts of sugar and salt. The diet should be coupled with at least 150 minutes of exercise per week, ideally spread over four or five sessions.
"There's no age where it's safe" to follow an unhealthy diet and exercise regimen, said Alan Braverman, a cardiologist and professor of medicine at the Washington University School of Medicine in St. Louis. "You can't start too early, and it's really a lifetime recommendation."
Experts cautioned that age itself is a significant risk factor. Though people age differently, in general, patients in their early 70s cannot treat their bodies the way they did decades earlier and hope to remain healthy.
"Ageing puts a dent in our physiology, our ability to lose weight, our exercise capacity," said Ranit Mishori, a professor of family medicine at the Georgetown School of Medicine. "That's just natural."
Trump's interview with Oz in 2016 came amid concerns about the health of his Democratic opponent, Hillary Clinton. Trump had gleefully seized on the issue and once imitated Clinton stumbling while falling ill at a 9/11 memorial event.
"I think you have an obligation to be healthy," Trump said. "I just don't think you can do the work if you're not healthy. I don't think you can represent the country properly if you're not a healthy person."
