King Charles spent the night at a central London hospital after undergoing treatment for an enlarged prostate and is said to be “doing well”.
It is not known how long the monarch will stay at The London Clinic, although reports suggest he could remain there throughout the weekend.
Queen Camilla appeared to be in good spirits as she smiled at reporters while leaving the hospital on Friday.
Buckingham Palace said last week that Charles, 75, would undergo the procedure this week for a benign condition which was common among men over 50.
The King is understood to have visited the Princess of Wales who is recovering after undergoing abdominal surgery at the same hospital.
According to PEOPLE magazine, the news of Kate’s hospitalisation came as a surprise to family friends and those who work closely with the royals, with “no indication that anything was wrong”.
It comes as Sarah Ferguson gave a health update while leaving a London hospital on Wednesday days after she revealed she had been diagnosed with skin cancer.