I spend a lot of time on hemochromatosis forums. And a constant theme are people convinced that their non-specific symptoms are caused by iron overload, when their blood work or genetic results indicate that this almost certainly isn't the case. Most of the complaints are the same type of vague symptoms that you find with Covid long-haulers: fatigue, joint pain, shortness of breath, brain fog. It's not a coincidence that those are also the same problems that occur with generalized unhealthiness.
Unfortunately a shockingly high number of Americans feel like shit all the time. Most of them are desperately seeking a silver bullet to explain their suffering. The sad reality is that the vast majority of cases come from getting older and unhealthy lifestyles. People are obese, they lead sedentary lives, they don't get enough sleep, their diets are all junk food, they smoke, they drink too much, they live with chronic stress.
The impact isn't so bad when you're young, but it wears you down fast when you start hitting middle age. So not only, do they feel crappy, but they're not accustomed to feeling this way. It's quite natural for anyone in that position to convince themselves that their ailments must be attributable to a specific disease.