Washington (CNN) The White House has offered shifting descriptions of President Donald Trump's medical exam in the days since he made an unscheduled Saturday visit to Walter Reed National Military Medical Center.

Trump and White House press secretary Stephanie Grisham initially billed Trump's visit as the first part of the President's annual physical. But two days later, the President's doctor described the hospital visit as an "interim checkup," a term physicians told CNN implies a separate visit that is not part of an annual physical.

In a bid to quell concerns and speculation surrounding the visit, the White House released a memo from Dr. Sean Conley , the President's physician, describing the visit as "a routine, planned interim checkup as part of the regular, primary preventative care he receives throughout the year."

Despite speculation otherwise, he said Trump "has not had any chest pain, nor was he evaluated or treated for any urgent or acute issues."

The immediate effect of Conley's memo was to bolster the White House's claims that Trump was not being treated for an urgent medical issue. But the memo also revealed a shift in the White House's explanations for the purpose of Trump's visit to Walter Reed.

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