As a presidential candidate in 2015, Donald Trump declined to release his medical records, instead offering a four-paragraph letter from his personal doctor proclaiming that he would be “the healthiest person ever elected to the presidency.”

In 2020, when he was hospitalized with COVID-19 and running for reelection, Trump’s doctors gave minimal information about his condition, which, it emerged later, was far more dire than their public descriptions let on.

In 2024, days before becoming the official Republican presidential nominee for the third time, he was grazed by a would-be assassin’s bullet, yet his campaign did not hold a briefing on his condition, release hospital records or make the emergency physicians who treated him available for interview.

Now, just over a month from an election that could make Trump, 78, the oldest person ever to serve as president (82 years, 7 months and 6 days when his term would end in January 2029), he is refusing to release even the most basic information about his health.

If he wins, Trump could enter the Oval Office with an array of potentially worrisome issues, medical experts say: cardiac risk factors, possible after effects from the July assassination attempt and the cognitive decline that naturally comes with age, among others.

Age became a major point of concern for voters weighing the capabilities of President Joe Biden, and a poor debate performance that showcased him struggling to articulate sentences ultimately forced him to withdraw from the race. Suddenly facing an opponent nearly 20 years his junior, Trump told CBS News in August that he would “very gladly” release his medical records to the public, saying he had recently had a medical exam.

The New York Times requested a copy of those records. A spokesperson for Trump eventually referred the Times to a one-page letter that his former physician, now a Republican member of Congress, wrote a week after the assassination attempt, describing the bullet wound to his ear and its progress in healing. The Times sent numerous follow-up questions. She did not reply.

Here is what is known about Trump’s health — and what is not.

Cardiac health

The most detailed overview of Trump’s health came in January 2018, when the White House physician, Dr. Ronny Jackson, briefed reporters after Trump’s first physical as president.

His blood pressure (122/74) and an ultrasound of his heart were normal, but his cholesterol was worryingly high and his body mass index put him just 0.1 points below the threshold for medical obesity.

Even though Trump was taking a statin, a drug used to lower cholesterol levels to well below 100, his LDL cholesterol was still 143 — so high that some outside cardiologists worried about his potential for a heart attack or stroke.

Jackson said Trump was 6-foot-3 (an inch taller than what was written on his driver’s license) and 239 pounds. A year later, his weight had risen to 243 pounds, the White House physician reported, making him officially obese.

At that point in 2019, he was taking a quadrupled dose of a statin — 40 milligrams daily, instead of 10 — and his LDL cholesterol had fallen to 122, still above the desired threshold even on that high a dose.

The next spring, the White House reported that Trump’s LDL had dropped below 100, though his weight was 244 pounds.

A 2023 booking record at the Fulton County jail in Atlanta, created when Trump was indicted on charges of election fraud in Georgia, listed his weight as 215, but he was not weighed at the jail, and his aides gave the figure on the form.

Trump’s most recent health update came in a three-paragraph letter from a new personal doctor, Bruce A. Aronwald, in November 2023, as the Republican primary campaign was heating up. It commended Trump twice for “weight reduction,” but did not say how much he weighed or give any details about medications or numerical results of any tests, only saying they were “well within the normal range,” “excellent” and “exceptional.”

When it comes to heart health, Trump has some factors working to his benefit: He has no history of smoking or drinking, and he does not have diabetes. But cardiologists agree that the health of a 78-year-old patient with a history of very high cholesterol cannot be adequately assessed using measurements taken more than four years ago.

Cognitive health

Trump’s father had Alzheimer’s disease. Trump has repeatedly said that he “aced” cognitive tests — most recently in August — but has not released any documentation.

Jackson said in 2018 that Trump took the Montreal Cognitive Assessment, or MoCA, a common 10-minute screening test to look for outright dementia. It asks participants to recite five words in order and repeat them later on; to identify a camel; and to draw a clock depicting 11:10, among other things.

It gives an overview of various domains of cognition — short term memory, executive function, spatial function, orientation and language — but it does not provide a detailed measure of any of them, experts said.

“It is not uncommon to see people who have mild cognitive impairment score normally on the MoCA, but by history and observation from others, they have cognitive problems,” said Dr. Jason Karlawish, an expert on neurology and aging at the University of Pennsylvania. “And it’s only when a clinician performs more detailed testing that reveals problems.”

In Trump’s debate against Biden this year, it was Biden whose performance was widely commented on, including by his allies, for exhibiting signs of aging. Dr. Jeffrey Kuhlman, who was the White House physician for Presidents Bill Clinton, George W. Bush and Barack Obama, said Trump’s more recent debate against Vice President Kamala Harris showed that “there’s no reasoning — he’s not taking in new concepts, he’s not forming arguments based on what she’s saying. He’s just spitting out rote memory.”

Trump has several times referred to Hillary Clinton or Biden as the “Obama administration,” and made so many verbal slips regarding cities, states and foreign leaders that his onetime presidential opponent, Gov. Ron DeSantis of Florida, started a “Trump accident tracker.” At rallies, he speaks in an increasingly disjointed manner.

Since he made clear in 2011 that he was considering running for president, Trump has been prone to going off-script and getting bored with his prepared remarks. But his digressions have become more frequent, and it has become harder to decipher the meaning of them or to determine a through line of his thinking.

Kuhlman, who has a forthcoming book on presidential health care — including a chapter on the physical and mental requirements of a president — said he believed that presidents and presidential candidates should undergo an in-depth neurocognitive assessment, administered by independent specialists, repeated periodically throughout the term and released to the public.

He said a baseline test would be useful if Vice President Kamala Harris won, too, given that she would be 68 by the end of a second term.

“If there’s one area that needs to be 100% in a chief executive — especially chief executive of the United States — it’s cognitive function,” said Anand Kumar, an expert in geriatric psychiatry at the University of Illinois Chicago.

Until recently, President Ronald Reagan dominated discussions about the risk of cognitive decline among aging presidents. Reagan was diagnosed with Alzheimer’s six years after leaving office, but his staff has said they noticed early signs of the issues during his term.

After the shooting

Millions of people have watched video of the moment when Trump grabbed his ear, dropped to the ground and emerged with blood streaming down his face. But the campaign has provided little information about what happened next — which makes it difficult to understand any implications for the long term.

Bystander videos show that Trump walked unaided into the emergency room of Butler Memorial Hospital.