I'm now 64 and have led a very physically busy active life - not through exercise for the sake (or love) of it that some do, mainly just practical stuff; a lot of building/DIY, fixing cars, all that sort of thing, all with (thank goodness) very little illness or injury. I have kept reasonably fit but not excessively so and, frankly, hate doing exercise for sake of exercise but will happily do a very long physically demanding day's work f it is needed - and often it is. So, I'm not lazy, I guess is what I'm saying, and thus not overweight (5'8"/174cm - 168lbs/72kg)
6 Years ago, I retired, divorced and sold the self-built 5 bed (literally) house of my dreams and moved 500 miles away to a remote Hebridean island where I intended to build another house to live out my days surrounded by the sea and my 'projects'. About 6 months before the move (and with a lot of stress going on planning the move - sea containers and all - and still living with the ex) I woke up in the middle of the night with my first bout of what I believe is palindromic arthritis/rheumatism (tho not diagnosed as such - doc here had never heard of it). Having gone to bed completely normal, I could not bear the pain from simply the weight of the duvet on my left (i think it was) big toe.
In the morning I couldn't walk on my left foot due to the pain and took my toe to the doctor. He sent me off to hospital for a blood sample suspecting gout (despite the complete lack of other gout symptoms nor a gouty lifestyle) and, surprise! - no elevated uric acid. His diagnosis was a viral infection and prescribed some pain killers. The pain steadily reduced over the next few days and after a week my foot was normal.
So began a period in my life of irregular bouts of the same thing each occurring in completely random locations on one or other foot - tho I have never had it as bad as the first occasion. Fortunately, my bouts a relatively few and far between (once every few months or so), come on often within an hour - and often also stop as quickly - going from severe pain to completely normal. The periods in between are also completely normal.
I am guessing there is a trigger or probably more likely a combination of factors that act together as a trigger and it is interesting comparing my situation with a good friend who contracted myalgic encephalomyelitis/chronic fatigue syndrome at the age of 30 having spent the first 20 years of her life in photography/marine science and was an avid sea kayaker, like her Dad.
It is, sadly, a sign of our times that drug companies are more interested in creating drugs to deal with symptoms than researching (and providing cures for) the causes of arthritis, in all its forms - why kill the golden egg-laying goose (he asked, cynically)?
I am an optimistic chap, overall, and see some huge advances coming soon to health in this field - and many others - due to the combination of the 'genome project' and artificial intelligence (one of the very few positive advances that AI will bring to humanity/the Planet, I suspect - humans being humans...).