King Charles' 'Swollen, Red' Hands Leave Royal Fans Worried: 'William Might Need To Start Preparing Himself'

King Charles III has been shaking hands with mourners across the U.K. since the death of his mother, Queen Elizabeth II, on Sept. 8, and it appears to be taking a toll on his hands.

Photos from King Charles' trip to Cardiff, Wales, Friday showed the 73-year-old monarch's hands and fingers looking red, raw and chafed after days of greeting citizens, Page Six reported.

Hundreds of people lined the streets outside Llandaff Cathedral Friday to get a glimpse of the monarch, who served as the Prince of Wales for 53 years before the title was passed on to his eldest son, Prince William, upon King Charles' accession to the throne.

During the greetings, the inner side of King Charles' hands appeared redder and more sensitive at the knuckles and joints of his fingers.. He has not addressed the reason behind it, but some social media users expressed concern.

"There's now been a few photos surfacing of the now King Charles' very, VERY swollen, red hands... Is this man OK? William might need to start preparing himself," one person tweeted.

"I've been wondering for a while now ... what's going on with Charles' big red hands?" another wrote.

"King Charles has red hands!! Any ideas?" a third user asked.

Some wondered if the appearance of King Charles' hands represented his health, as Queen Elizabeth II was seen with dark blue bruising on her hands just two days before she died.

Following Queen Elizabeth's passing, Australia-based Dr. Deb Cohen-Jones examined photos of Her Majesty's hands as she posed alongside the U.K.'s new Prime Minister Liz Truss at Balmoral Castle in Scotland on Sept. 6.

The doctor told Mail Online that the Queen's "mottled hands" could be an indication of "peripheral vascular disease," a blood circulation disorder.

"It looks like there is possibly evidence of peripheral vascular disease. It's a blood circulation disorder that causes the blood vessels outside of your heart and brain to narrow, block, or spasm," Cohen-Jones explained. "It can sometimes result in heart failure. If your peripheral circulation is that poor, organs aren't receiving a good blood supply. It can be a sign of multi-organ failure."

Queen Elizabeth will be honored with a state funeral at Westminster Abbey in London Monday, to be followed by a Committal Service at St. George's Chapel at Windsor Castle, where she will be laid to rest. All working members of the royal family with military rank will wear their uniforms.

Prince Harry and Prince Andrew, who are no longer working royals, are expected to appear in mourning attire, or dark suits. However, both royals have been allowed to wear their military uniforms to a special vigil for the Queen this weekend.