What is the real state of Trump’s health?

If Trump’s health is more troubled than usually terse official statements are letting on, he would not be the first president for whom this is the case. The physical and cognitive condition of presidents has been a key avenue of inquiry for historians of Woodrow Wilson, Franklin D. Roosevelt, John F. Kennedy, and Ronald Reagan.

What was that unscheduled trip to Walter Reed Army Medical Center last November all about? What explains Trump’s unsteady appearance drinking water or walking down a ramp at West Point earlier this month?