Prince Phillip, the Duke of Edinburgh, was admitted to hospital today as a 'precautionary measure' due to the recurrence of a bladder infection.
BBC News reported the 91-year-old is expected to remain in Aberdeen Royal Infirmary, near his Balmoral residence, for a few days.
Prince Philip had been on his summer break at Balmoral, in Scotland, with the Queen when he became ill.
CNN said Prince Philip has suffered a couple of health scares in the past year.
Prior to the bladder infection, which Prince Philip contracted in early June, during events marking the queen's diamond jubilee, he suffered a blocked coronary artery and spent four nights in a hospital over the Christmas holiday last year.
However, numerous media reported that he appeared well earlier this week as he fulfilled several engagements on the Isle of Wight, off the south coast of England.
The Telegraph reported bladder infections are common among elderly men, particularly those who have prostate problems that leave them unable to empty their bladders properly.
Apart from being painful, they can sometimes be a sign of a more serious underlying problem and so sufferers are usually taken to hospital and treated with antibiotics or a drip for rehydration.
While the Duke’s condition is not believed to be serious, doctors will not be taking any chances, given his advancing years.