Queen Elizabeth II Under Medical Supervision as Health Concerns Grow

LONDON — Queen Elizabeth II’s health appeared to be deteriorating on Thursday, with Buckingham Palace announcing that she had been placed under medical supervision and that her doctors were “concerned” about her health.

The queen, who is 96, has not been hospitalized and remains at Balmoral Castle, her estate in the Scottish Highlands, the palace said in a statement. But on Wednesday evening, she abruptly canceled a virtual meeting with members of her Privy Council after her doctors advised her to rest.

“Following further evaluation this morning, the queen’s doctors are concerned for Her Majesty’s health and have recommended that she remain under medical supervision,” the palace said in a statement.

On Tuesday, the queen looked frail in a meeting with the incoming British prime minister, Liz Truss.

“The whole country will be deeply concerned by the news from Buckingham Palace this lunchtime,” Ms. Truss said in a Tweet on Thursday. “My thoughts — and the thoughts of people across our United Kingdom — are with Her Majesty The Queen and her family at this time,” she said.