President Donald Trump's blood oxygen levels fluctuate, and he suffered from a fever, the President's Chief of Staff has revealed.

On Friday, President Trump's health raised alarms among doctors and aides that day as he faced a crucial time in his battle against the coronavirus, according to Chief of Staff, Mark Meadows. On the same day, hours after Trump revealed that he tested positive for COVID-19, Trump was flown to Walter Reed Hospital, according to The Sun.

While staying in the hospital, the Republican President posted a video from his hospital suite on Saturday. He warned he faced a "real test" in the coming. However, President Trump promised to be back soon and to finish the campaign.

Meadows and White House physician Dr.Sean Conley were "really concerned" about the 74-year-old president and on his condition on Friday morning, Meadows told Fox News host Jeanie Pirro. "He's made unbelievable progress from yesterday morning when a number of us - the doctor and I - were very concerned," Meadows said.

Trump's Blood Oxygen Levels Drop When Rushed to Hospital, Chief of Staff Reveals
President Trump Tests Positive For Coronavirus WASHINGTON, DC - OCTOBER 02: White House Chief of Staff Mark Meadows speaks to reporters about President Trump's positive coronavirus test outside the West Wing of the White House on October 2, 2020 in Washington, DC. President Donald Trump and First Lady Melania Trump have both tested positive for coronavirus. Drew Angerer

According to Meadows, on Friday morning, they were really concerned when the President had a fever and blood oxygenation immediately dropped. He added that he had spoken to President Trump several times that time and the President gave him tasks to do.

"He continues to be not only in good spirits but very energetic," Meadows said. Meadows complimented Trump and said that the great thing about him is not only Trump is staying committed working very hard for the Americans, "but his first question to me this morning was: "How are the stimulus talks going on Capitol Hill? How is the economy doing?"

Meadows sparked confusion on Saturday morning after he told reporters that the road recovery is unclear which gave people a far less optimistic view of President Trump's condition.

Meadows said President Trump's vitals over the last 24 hours were very concerning and the next 48 hours are crucial in terms of Trump's care. "We're still not on a clear path to a full recovery."

Trump received supplemental oxygen at the White House prior to his hospital admission, according to the reports. Although, Dr.Conly refused to confirm the details amid President Trump's update on Saturday afternoon.

Alongside nine other members of the President's medical team, Dr.Conly said that President Trump was in "exceptionally good spirits" and that the President had said, "I feel like I could walk out of here today."

Conly also confirmed that President Trump made substantial progress since his diagnosis and that the President took two doses of Remdesivir. "President Trump remains fever-free and off supplemental oxygen with a saturation level between 96 and 98 per cent all day," he said.

According to Conly, President Trump spent most of the afternoon in business and has been moving up about the medical suite with no difficulty. The President's medical team remains cautiously optimistic.

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