"She has pneumonia,” Reid continued. “She's off the campaign trail for a few days. She probably needed the rest anyways."
The retiring Nevada Democrat, who has used his podium in the Senate to rail against the GOP presidential nominee, urged reporters to "take a look at this character that is running for president."
"He complains about her health. What does he do? He’s 70 years old, he’s not slim and trim," Reid said.
"He brags about eating fast food every day."
Both Trump, 70, and Clinton, 68, have revealed far less about their medical history than previous Republican and Democratic presidential nominees.
In July of 2015, Clinton's doctor released a two-page statement on Clinton's health, describing her as a "healthy 67 year old female whose current medical conditions include hypothyroidism and seasonal pollen allergies."
"She is in excellent physical condition and fit to serve as President of the United States," Dr. Lisa Bardack wrote.
Trump's doctor released a one page statement in December that said the New York developer would be the "healthiest individual" ever elected president.
In 2008, Sen. John McCain, who was 71-years-old at the time, released nearly 1,200 pages of health records.
Both candidates' campaigns have said they plan to release additional medical records.