Donald Trump has had a stroke, a prominent clinical professor of medicine said, listing evidence he said he saw in the president's behavior.

"My impression is that President Trump has had a stroke, and I think there's several lines of evidence supporting that," said Professor Bruce Davidson, of Washington State University Elson S. Floyd College of Medicine, in Spokane, Washington. "I think his stroke was on the left side of the brain, which controls the right side of the body."

Davidson was speaking to the Clinton aide turned Lincoln biographer Sidney Blumenthal and Princeton historian Sean Wilentz on their podcast, The Court of History.

Now 79, Trump is the oldest president ever to assume office. Speculation over his health has been a persistent feature of his second term. Physical slips have been noted, as have occurrences in which Trump has appeared to sleep during daytime events. Slurred speech and difficulty forming sentences have been widely remarked upon.

Trump regularly claims to be in excellent mental and physical health — claims backed up by White House statements.

On The Court of History, Davidson was asked what formed his belief about the president's health.

He said, "I think the stroke was six months ago or more, earlier in 2025. There's video of him shuffling his feet, which is not what we'd seen him [doing], striding on the golf course … previously. We've seen him holding his right hand in his left, cradling. And earlier in the year, in 2025, he was garbling words, which he didn't do previously, and which he's improved upon more recently. And he's also had marked episodes that have been noticed of daytime, excessive sleepiness, — medical term, hypersomnolence — which is characteristic of many patients after they've had a stroke. … Most recently, there was video of him walking down the stairs from Air Force One, holding the banister with his left hand, although he's right-handed, and all of this is consistent with having had a stroke on the left side of his brain. A stroke is an area of infarction. It's an area of dead tissue."

Davidson also described behavior he said he thought showed Trump's psychological reaction to surviving a stroke.

"People who … have a stroke, it's a very serious, concerning, life-threatening, upsetting, scary thing, and people react in different ways," Davidson said. "Some people respond with humility, grateful to be alive and viewing life as precious. Others become, as they improve, positively euphoric, that, 'I was at the cliff of death, and now I'm back,' and and some view it as, 'That was my chance to die, and I didn't, and now I'm going to do everything I wanted to do, because the next one may be fatal."

The accelerating pace of Trump's policy announcements, military orders, demands for the prosecution of enemies, and attacks on political opponents has been noted around the world.

Referring to Trump's regular claims about his own health, Davidson said: "Another piece of evidence in favor of him having had a stroke is his telling us that he's taking a whole aspirin tablet, 325 milligrams daily."

Trump said that this month, in an interview with the Wall Street Journal, about his health. Saying the aspirin had caused widely noted bruising on his hand, Trump told the Journal: "They say aspirin is good for thinning out the blood, and I don't want thick blood pouring through my heart. I want nice, thin blood pouring through my heart. Does that make sense?"

To Davidson, it did not.

"The instruction to take one full aspirin, 325 milligrams daily, is solely, only for prevention of recurrent repeat stroke after partial 50 percent or more blockage, occlusion of a large vessel in the brain," the doctor said. "It's not recommended for anything for the heart, and we were told that President Trump's chest CT scan was unremarkable, was fine."

Trump recently said he had an MRI, then said it was in fact a CT scan.

Davidson told Blumenthal and Wilentz: "A CT scan of the chest takes three or four minutes, and when you add the abdomen, that's another three or four minutes. An MRI is what we use to most carefully image the brain. You can image the brain pretty well with a CT scan, and that's emergency imaging of the brain, because it's more available, but an MRI gives you far more detail, and an MRI takes a minimum of 20 minutes, and they put this over your head, and it's extremely noisy, it's a banging sound, and they put headphones to block the sounds. So there is no mistaking an MRI for CT. And when President Trump said he had an MRI, he undoubtedly did. Now we do MRIs of the spine, of bone and joints. But that's not what he was talking about when he talked about cognitive testing. So I think it's, it's certainly clear that did not sound like a misspeaking, that he had an MRI of his brain and he had CT, surveillance, CAT scans of his chest and abdomen."

Blumenthal and Wilentz noted that presidents have suffered strokes in office — Woodrow Wilson's was hidden from the public, while Franklin D. Roosevelt died.

Trump has also regularly boasted about passing basic cognitive tests, adding to widespread speculation that the president could be suffering from dementia. Davidson did not think so.

"He doesn't, to me, behave demented," he said, adding: "It seems to me that with those New York Times questions recently and press conferences, he grasps the question and appropriately responds — or inappropriately, depending on your views — but he certainly handles the gist of the question. So I do not see dementia, for which I'm glad, but it is common after strokes for people to behave, as some people say, more like they were beforehand. So if President Trump had a brash personality, I think everyone would say, long ago, he appears to have become even more so."

Davidson said there would be no current reason to invoke the 25th Amendment because Trump appears functionally capable, at least from a superficial perspective. He emphasized that many people recover from strokes while retaining their judgment and ability to perform complex work, though such recovery typically requires support from trusted advisors, whether family or colleagues.

"I think there could be a way for President Trump to thread the needle," he said.

Davidson suggested Trump could navigate this situation by acknowledging a stroke without losing cognitive function, thus avoiding the need for temporary replacement. In this scenario, with proper support from advisors whom he heeds, along with attention to diet, medication, exercise, and intellectual engagement, Trump could continue serving as president despite the health event.

"There is no need to get all exercised about that issue. But I think it'd be good for the public to be informed. That's just the nature of my view of the way I was trained in elementary and junior high school about democracy," he said.