The Queen has revealed she was left "very tired and exhausted" by her bout of COVID-19 during a virtual meeting of hospital staff in London.
Her Majesty tested positive for the virus in February and had what Buckingham Palace described as "mild cold-like symptoms".
Speaking at the virtual official opening of the Queen Elizabeth Unit at Royal London Hospital, the Queen said of coronavirus: "It does leave one very tired and exhausted, doesn't it? This horrible pandemic. It's not a nice result."
The Queen, 95, was speaking to Asef Hussain, one of 800 people treated at the north-east London hospital, which was built in five weeks during the pandemic to meet demand.
Mr Hussain was the third member of his family to go to hospital with COVID-19 when he fell ill in December 2020.
His brother died, followed by his father, who passed away while Mr Hussain was on a ventilator.
He told the Queen that his wife, Shamima, called 999 after he struggled to catch his breath.
"I remember waking up one morning and just finding it really, really difficult to breathe," he said.
"I remember waking my wife saying that I feel like there's no oxygen in the room. I remember me sticking my head out the window, just trying to breathe, trying to get that extra oxygen."
Mr Hussain was on a ventilator at the hospital for seven weeks and is still recovering from the illness, only having recently stopped using a wheelchair.
His wife told the Queen that there were 500 friends and family from across the world praying for her husband, to which the monarch joked: "So you have a large family, or a large influence on people?"
The Queen listened to other stories from patients and staff, with one nurse telling her: "We held their hands, we wiped their tears and we provided comfort."
Senior sister Mireia Lopez Rey Ferrer, who has worked in the hospital since 2008, described her team's commitment to their patients.
"As nurses we made sure that they were not alone," she said.
"It felt at times that we were running a marathon with no finish line."
"I look back to the last 18 months with great pride, pride not only in the care we provided to each and every single patient, that was in one of our hospital beds, but pride in each member of staff that every day they left their families at home despite their fears and worries and they came to work."
The Queen also spoke to the construction team that built the unit on the hospital's 14th and 15th floors, telling them: "It is very interesting, isn't it, when there is some very vital thing, how everybody works together and pulls together - marvellous isn't it?"
When members of the team said it was the "Dunkirk spirit", Her Majesty replied: "Thank goodness it still exists."