Factbox: The health of Britain's Queen Elizabeth

Buckingham Palace tries to avoid releasing details about her health as it says medical matters are private.

* COVID: "The Queen has today tested positive for COVID," Buckingham Palace said. "Her Majesty is experiencing mild cold like symptoms but expects to continue light duties at Windsor over the coming week."

"She will continue to receive medical attention and will follow all appropriate guidelines," the Palace said.

* "I can't move" - Elizabeth on Feb. 16 quipped to members of the royal household that she could not move much as she carried out her first in-person engagement since her son Prince Charles tested positive for COVID-19, a few days after he had visited her.

"Oh, I am here," the queen, supporting herself with a stick, chuckled as the outgoing and incoming defence services secretaries entered her room.

When asked how she was, the queen responded: "Well, as you can see, I can't move." She gestured at her feet before shuffling forward slightly and greeting the pair with a handshake.

* Remembrance Day Service - Elizabeth pulled out of the Remembrance Day ceremony on Nov. 14 at the Cenotaph war memorial in London on Sunday with a sprained back.

She was back at work at Windsor three days later.

* COP26 - In late October, Elizabeth withdrew from attending the COP26 summit in Glasgow following advice from doctors to rest.

* Hospital: Elizabeth spent a night in hospital on Oct. 20 for the first time in years for what Buckingham Palace termed 'preliminary investigations'. She returned to Windsor Castle the next day.

On the day Elizabeth went to hospital, Buckingham Palace had said simply that the monarch had been told to rest for a few days. Her hospital visit came to light later.

A royal source said the queen had stayed in hospital for practical reasons and that her medical team had taken a cautious approach.

* Alcohol and riding: British media reported that Elizabeth had in 2021 given up her daily dry martini and even been forced to give up horseriding.

* Eye cataract: In 2018, Elizabeth, then 92, underwent successful surgery to treat an eye cataract. Cataracts are when the lens, a small transparent disc inside your eye, develops cloudy patches.

*A heavy cold: In 2016, Elizabeth, then 90, and her husband, Philip, got heavy colds. She missed a traditional Christmas church service for the first time in decades.

* Gastroenteritis: In 2013, the queen was treated for gastroenteritis when she was 86.

* 1981: A British man fired six blank shots at the queen as she rode along the Mall during a Trooping the Colour ceremony. The queen was unharmed. Her horse tried to bolt but she controlled it and carried on with the procession.