Royal experts think Prince Philip would have encouraged Queen Elizabeth to take a step back from royal duties if he was still alive.
The British monarch spent a night in hospital for tests after being forced to cancel a visit to Northern Ireland, and now royal biographer Angela Levin has suggested the Queen's late husband - who died in April aged 99 - would have wanted her to take care.
She said: "If Prince Philip was still around, he would have exercised a 'bit of control' and told his wife: 'Look, stop it, don't go to so many engagements and relax a bit."
The biographer went on to say that we should be persuading the 95-year-old monarch to prioritise her health over royal duties after losing Philip earlier this year.
Speaking to talkRADIO, Angela added: "We've got to sort of encourage her to take a step back or sideways or something to allow her body to recover from the engagements that she does.
"I think it's a fight between her head and her body, because she wants to do it, she feels she can, she's very articulate, she's absolutely spot on with everything she says, but her body is 95 years old."
The royal expert - who has charted the monarchy in books such as 'Harry: Conversations with the Prince' and 'Diana's Babies: Kate, William and the Repair of a Broken Family' - went on to cite the Queen's religion as a possible reason for her unwavering work ethic.
She said: "I think she thinks she does it best [compared to other royals] and she's the most experienced, but I think the main thing is the religious one, that when she was 21 and she said that she would do her best to be the Queen and with God's help she would do it until she died.
"The coronation actually confirmed that as it is a holy event as well as a royal one, and she doesn't want to break her link with that. It would make her feel very bad because she is devout."