MSNBC's Mika Brzezinski on Monday said Hillary Clinton's campaign should have "absolutely" announced that she had pneumonia.

During a "Morning Joe" panel discussion, Brzezinski responded to a question from Bloomberg's Mark Halperin about whether Clinton should have revealed the diagnosis.

"Absolutely — the issue is, how much is the campaign going to stumble and lead people down the untrustworthy lane?" Brzezinski said. "We need transparency from this candidate, we need press conferences. We need everything to be as transparent as possible, given the legacy — the Clinton legacy."

Clinton on Sunday left a Sept. 11 Commemoration Ceremony after feeling unwell.

Her personal physician later said she had been diagnosed with pneumonia on Sept. 9, but continued with her campaign schedule.



NBC News' Kristin Welker, also appearing on "Morning Joe," said Clinton felt that she could take medicine to treat her pneumonia and continue to campaign.

"Secretary Clinton felt that she could power through. She wasn't coughing on Saturday, so she felt that she could take those antibiotics and continue with her regular schedule," Welker said. Adding that Clinton's campaign "now realizes that was a big mistake."

Democrats might treat the episode as a sign of Clinton's strength, Welker continued, noting that after her pneumonia diagnosis, she attended two fundraisers, held a two-hour meeting with a security team, did a network TV interview, and held a press conference.

Dr. Emily Senay from the Icahn School of Medicine at Mt. Sinai, also on the panel, said Clinton's pneumonia was "concerning" and without more discussion about Clinton's health, there's no way to tell how quickly she could bounce back.

Walking pneumonia is common and it's "kind of a run-of-the-mill thing that general practitioners see all the time that people have, they get over, they go back to work, no big deal," Dr. Senay said.

Clinton's medical history as has been reported, Dr. Senay continued, does not appear to be a concern relative to her pneumonia because "she's 68-years-old. Stuff happens over a lifetime."

The Democratic nominee has canceled a trip to the West Coast while she recuperates at home in Chappaqua, New York.

Critics have pointed out questions about her health, but the Clinton campaign dismissed them as a "wacky strategy."

Republican rival Donald Trump on Monday said he hopes "she gets well soon."