The Queen is resting at Windsor Castle after cancelling a planned visit to Northern Ireland on the advice of her doctors.
The Queen had “reluctantly accepted medical advice” to rest for the next few days, Buckingham Palace said.
She was said to be in “good spirits” but “disappointed” not to be able to fly to Northern Ireland for a busy two days of public engagements.
The announcement came amid fears the Queen may be doing too much, with a packed diary of engagements since she returned from Balmoral at the beginning of October.
Since then, she has undertaken seven public events, including travelling to Cardiff, as well as her usual workload of audiences, investitures and dealing with daily red boxes.
On Tuesday night, she appeared to be on sparkling form at a Windsor Castle reception for business leaders and showed no sign of feeling unwell.
In a statement released at 11am on Wednesday, the palace said: “The Queen has reluctantly accepted medical advice to rest for the next few days.
“Her Majesty is in good spirits and is disappointed that she will no longer be able to visit Northern Ireland, where she had been due to undertake a series of engagements today and tomorrow.
“The Queen sends her warmest good wishes to the people of Northern Ireland, and looks forward to visiting in the future.”
The Telegraph report that the decision to cancel was not related to Covid-19, a source confirmed, emphasising that there is no cause for concern about Her Majesty’s general health.