Standing on the steps of Walter Reed National Military Medical Center on Monday, with a phalanx of white-coated doctors behind him, the White House physician, Dr. Sean P. Conley, ticked off President Trump’s encouraging vital signs: no fever, only slightly elevated blood pressure and a blood oxygen level in the healthy range.
“He’s back,” Dr. Conley said later in the news conference.
But when reporters asked him for results of Mr. Trump’s chest X-rays and lung scans — crucial measures of how severely the president has been sickened by Covid-19 — Dr. Conley refused to answer, citing a federal law that restricts what doctors can share about patients.
Without critical data about his lung function, medical experts in Covid-19 and lung disease said they were struggling to piece together an accurate picture of how Mr. Trump is faring. They noted that while most patients with the virus do recover, it