On May 6, the Archbishop of Canterbury, Justin Welby, carefully placed the iconic St. Edward’s Crown atop King Charles III's head as the new king solemnly sat in the 700-year-old Coronation Chair at Westminster Abbey while grasping a golden scepter in each hand.

It was the first time in 70 years for a monarch to be crowned in the U.K. since the coronation of his late mother, Queen Elizabeth II, who shared an almost identical pose, wearing the same crown in 1953.

When his mother died on Sept. 8, 2022, he became the oldest monarch to take the British throne.

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The king is now 74 (he'll turn 75 on Nov. 14, 2023) — and many wonder if the monarch will enjoy the same longevity as his parents did.

"I expect King Charles’ reign to be a long one," Dr. June McKoy, professor of medicine, preventive medicine and medical education at Northwestern University Feinberg School of Medicine in Chicago, Illinois, told Fox News Digital. 

"That he is starting his reign in his 70s will not prevent him from doing as well as a monarch in his 40s," added McKoy, who is an academic geriatrician. 

She recommended that older adults be individually assessed and not by chronology as they age.

"To be sure, King Charles has been a great steward of his health and he will benefit from that stewardship."

King Charles III comes from a family of "long livers" on both his mother’s and father’s side, so it’s likely he inherited their genes, McKoy said. 

"The latest science on the genetics of longevity suggests that, for most of us, less than 20% of it is passed down through the generations, meaning the other 80% is lifestyle and luck," Andrew Steele, PhD, author of "Ageless: The New Science of Getting Older Without Getting Old," told Fox News Digital.

"However, there does seem to be a more significant genetic component when it comes to exceptional longevity — the child or sibling of someone who lives to 100 is 10 times as likely to do so themselves as someone from the general population," added Steele, a biologist based in Berlin, Germany.

Charles’ father lived to 99, his mother lived to 96 and his grandmother, the queen’s mother, lived to 101 — so he may be lucky enough to have some longevity genes in his DNA, he added.

"Wealth is known to correlate with long life, too, so even though he ascended to the throne at age 73 — the oldest in British history — he's still got a shot at a decently long reign," Steele said in an email.

Charlies turned 74 in November 2022. (None of the medical experts interviewed for this article directly examined King Charles III.)

Prince Harry, Charles’ youngest son, wrote in his bombshell memoir, "Spare," that his father used to perform handstands in Balmoral Castle to relieve chronic back and neck pain from old polio injuries.

"Prescribed by his physio, these exercises were the only effective remedy for the constant pain in Pa’s neck and back," Harry wrote. 

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"He performed them daily, in a pair of boxers, propped against a door or hanging from a bar like a skilled acrobat."

After missing the Royal Ascot, one of Britain’s most famous horse races, because of a herniated disc in his spine in 1991, Charles aggravated the condition when he fell off a horse at Windsor two years later, according to a Daily Mail report. 

Experts speculate that his trademark walk with his fingers interlocked together behind his back is a clever way to relieve his back pain. 

"On another note, there has been some focus on his posture and its implications for osteoporosis," McKoy told Fox News Digital.

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"Given that osteoporosis causes a decrease in bone density and weakening of the bones, it can cause height loss," she added. 

A stooped posture might represent height loss, she said — but this can be normal or abnormal depending on the individual circumstances.

As part of the normal process of aging, people typically lose approximately 1 centimeter, or 0.5 inch, of height every 10 years — which tends to accelerate in our 70s, McKoy said. 

She also said, "Height loss of [two] inches or more is not considered normal and should prompt a visit to the physician."

King Charles suffered many injuries while playing polo and hunting, including a pivotal fall during a polo match in 1990 that resulted in fracturing his right arm.

After it didn’t heal once he had surgery, he had a second operation to fix it three months later, partly due to concern the injury would not allow him to properly salute, per a Daily Mail report.

In 2001, Charles was knocked unconscious temporarily when he fell head-first from his horse during a charity match at Cirencester Park in Gloucestershire, England, according to a BBC report.

He retired from polo in 2005 when he was 57, after playing the game for over 40 years, as his biography on his official website said.

"He has an interesting pair of hands for a baby," Queen Elizabeth wrote to her former music teacher shortly after her son Charles was born. 

"They are rather large, but with fine long fingers quite unlike mine and certainly unlike his father's." 

Charles himself referred to them as "sausage fingers" after Prince William’s birth, according to Howard Hodgson’s biography "Charles, The Man Who Will Be King."

"Dactylitis is a condition where the digits get swollen like sausages, typically seen in the toes and associated with ankylosing spondylitis," Dr. Nilanjana Bose, a board-certified rheumatologist at Lonestar Rheumatology in Houston, Texas, told Fox News Digital. 

It’s important to examine the hand to distinguish if the swelling is arising from the joint, the tendon sheath or the soft tissue, added Dr. Amy Kehl, rheumatologist with Providence Saint John’s Physician Partners and staff physician at Cedars Sinai in Southern California.

Bose said the look of Charles' hands could be his "baseline" and not suggestive of any underlying disease. 

"True dactylitis is most classically observed in patients with a type of inflammatory arthritis known as spondyloarthritis," Kehl told Fox News Digital.

One example of this type of arthritis, she said, is psoriatic arthritis, which is often diagnosed by examining the patient.

There are a variety of medical conditions that can cause swollen fingers, including other types of arthritis — such as rheumatoid arthritis, gout, autoimmune causes — like lupus, sarcoidosis or sickle cell disease, or infections, such as Lyme disease, syphilis and tuberculosis. 

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"Typically a rheumatologist can order more diagnostic testing including lab testing or imaging studies of the joints if the diagnosis is unclear," Kehl said. 

"The typical treatment is geared toward the underlying type of inflammatory arthritis and the degree of symptomatology of the individual patient."

"Understanding the biology of people who make it to exceptional ages could be an important way to discover medicines that can help us all live longer and healthier," Steele noted.

"For example, while women live longer than men, we know that long-lived men tend to do so in better health," he added.

Steele also said he hoped that "Charles will be a 'working royal' for some time yet."