The King has sought treatment for an enlarged prostate and will attend hospital next week for a corrective procedure, Buckingham Palace confirmed on Wednesday.
In statement the palace shared: "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."
It's understood that the King, 75, was keen to share the details of his diagnosis to encourage other men who may be experiencing symptoms to get checked in line with public health advice.
According to the NHS website: "Benign prostate enlargement (BPE) is the medical term to describe an enlarged prostate, a condition that can affect how you pee (urinate). BPE is common in men aged over 50. It's not a cancer and it's not usually a serious threat to health."
The King had a series of meetings and events planned at Dumfries House in East Ayrshire on Thursday and Friday, which are now being postponed on his doctor’s advice.
Guests, including foreign dignitaries and members of the Cabinet, were due to travel to Scotland and the Palace made the announcement to allow for them to be made aware of the situation.
Charles was last seen publicly on Sunday when he attended a church service with Queen Camilla at Crathie Kirk near the Balmoral estate.
The King and Queen have been residing at their Scottish home, Birkhall, since the start of the year following their Christmas break at Sandringham.
The news about the King's medical procedure comes just hours after Kensington Palace announced that Charles' daughter-in-law, the Princess of Wales, was recovering in hospital following planned abdominal surgery.
In a statement, the palace said: "Her Royal Highness The Princess of Wales was admitted to hospital yesterday [Tuesday] for planned abdominal surgery.
“The surgery was successful and it is expected that she will remain in hospital for ten to fourteen days, before returning home to continue her recovery. Based on the current medical advice, she is unlikely to return to public duties until after Easter.
“The Princess of Wales appreciates the interest this statement will generate. She hopes that the public will understand her desire to maintain as much normality for her children as possible; and her wish that her personal medical information remains private.
“Kensington Palace will, therefore, only provide updates on Her Royal Highness’ progress when there is significant new information to share.
“The Princess of Wales wishes to apologise to all those concerned for the fact that she has to postpone her upcoming engagements. She looks forward to reinstating as many as possible, as soon as possible.”