The King has gone into hospital for prostate treatment, Buckingham Palace has said.
In a statement, it added: “The King was this morning admitted to a London hospital for scheduled treatment.
“His Majesty would like to thank all those who have sent their good wishes over the past week and is delighted to learn that his diagnosis is having a positive impact on public health awareness.”
The Queen entered the London Clinic hospital with him.
It is the same hospital where their daughter-in-law, the Princess of Wales, is staying having undergone abdominal surgery.
It is understood that the King visited her ahead of his own treatment, according to Press Association.
The King‘s public engagements will be postponed after he has his corrective procedure on an enlarged prostate.
It is understood he shared details of his diagnosis to encourage other men who may be experiencing symptoms to get checked in line with public health advice.
The palace announced last week that he would be having treatment less than two hours after it was announced that his daughter-in-law had undergone abdominal surgery and will remain in hospital for up to two weeks.
In a statement, the palace said: “In common with thousands of men each year, the King has sought treatment for an enlarged prostate.
“His Majesty’s condition is benign and he will attend hospital next week for a corrective procedure.
“The King’s public engagements will be postponed for a short period of recuperation.”
The Queen said during an engagement in Aberdeen on 18 January that the King is “fine” ahead of his treatment and was “looking forward to getting back to work”.
The NHS describes a benign enlarged prostate as a condition that can affect how people urinate, and is common among men aged over 50.
“It’s not a cancer and it’s not usually a serious threat to health,” the NHS said on its website.
“Many men worry that having an enlarged prostate means they have an increased risk of developing prostate cancer. This is not the case.”
But benign prostate enlargement can sometimes lead to complications, such as a urinary tract infection, chronic urinary retention, and acute urinary retention.
The NHS also said the cause of prostate enlargement is unknown, but it is believed to be linked to hormonal changes as a man gets older.