president in mystery. want to talk with sanjay gupta who is also naur of the fascinating new book, world war c lessons from the covid-19 pandemic and how to prepare for the next one. so, sanjay, what can you tell us about the results of this physical? >> well, we had some idea of some of the president's past medical history. we also know he is the oldest first-term president. so putting those two things together, there were specific things that i think they were sort of targeting. we know that he has this history of reflux, for example. we know he has a history of atrial fibrillation. they were focused on the fact that his -- his gait -- his walking, anderson, seems to have changed a bit. they describe it as being less fluid, stiffer gait. we also know he takes this medication for his cholesterol and he had a colonoscopy. so those were sort of the major things that came out of that and there -- there were a few findings. his reflux is still persistent which is why they think he's been coughing a lot. you may hear him clearing his