WHITE PLAINS, N.Y. — Hillary Clinton returns to the campaign trail Thursday following a bout of pneumonia that sidelined her for three days and revived questions about both the Democratic nominee and Republican Donald Trump’s transparency regarding their health.

Clinton’s campaign responded with a new letter from her doctor Wednesday declaring her “fit to serve” as president and recovering well from her recent illness. The letter — the first substantial update on her health in more than a year — details the medications she is taking, her cholesterol levels and other results from a physical exam.

In a taped radio interview broadcast Thursday morning, Clinton told the “Tom Joyner Morning Show” that she was feeling much better and was “really glad that I did finally follow my doctor’s orders and take some days to rest instead of just trying to keep powering through, which I think is a common experience for people.”

Trump says he, too, plans to release details from a recent physical, though it’s unclear when that will happen and how much information he will provide. So far, the businessman has only released a widely mocked letter from his longtime physician declaring he would be the healthiest president in history.

In keeping with Trump’s unusual approach to transparency, the Republican handed over a one-page summary of his recent exam to Dr. Mehmet Oz while taping an episode of Oz’s show. A release from the show said “Dr. Oz took Mr. Trump though a full review of his systems,” including his nervous system, cardiovascular health, prostate health and family medical history.

The show is due to air Thursday. Trump’s campaign has not made a copy of the summary public ahead of the airing, nor is it certain he will do so after. Trump said in a phone interview Thursday interview with “Fox and Friends” that he is 6-foot-3 and 236 pounds — giving him a body mass index falling into the “overweight” range. He discussed results of his physical ahead of the airing Wednesday of a taped interview with TV personality “Dr. Oz.”

While Clinton has released more information than Trump — both about her health and financial history — her campaign’s handling of her illness underscored her penchant for privacy, something that has contributed to the public’s lack of trust in the former secretary of state.