“Charles is no spring chicken anymore. The global travel takes its toll on him – not to mention all the problems back at the palace.”
Adding to Charles’ stress is also said to be the bombshell new BBC Two documentary, The Princes and the Press, about the palace’s murky relationship with the media.
What’s more, the first in line to the throne is said to be “deeply concerned” for his mother, who temporarily stepped back from public duties following a sprained back and a separate undisclosed medical issue.
“Charles is worried sick about her and it’s a burden to him,” the source explains.
Since his father Prince Philip’s death in April, Charles has been checking in on his mother to the point where the Queen has instructed her staff to “fend off his calls so she can get some rest”.
Charles first raised eyebrows surrounding his health in July, when he was seen looking frail as he struggled to stand up at a palace appearance in Wales.
“He came perilously close to a fall,” an onlooker said during his visit, also noting his bloated hands.
“Charles is a sensitive man who has always taken things too seriously and personally, and it’s really starting to reflect on his health,” tells a source, who says it’s now a case of having his team reassess his duties and appearances in order to “maintain his wellbeing”.
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“It’s hard to imagine how he can possibly go on like this, with the workload taking its toll on Charles before his accession to the throne – something has to change,” adds the source.
Read more in this week's New Idea, on sale now.