This is a good question! I had quite few early signs that were treated independently and not linked to each other: pain in the spine in my late teens, tennis elbow late twenties, and inflammation of Achille's in early thirties.
I mention them because these pains and inflammation came out of the blue, without injuries, and took some time to heal...so already a sign of a chronic inflammation in my body. I used Osteopathy, physiotherapy, and homeopathy to manage these and lot of patience to heal these inflamed joints. I realise it was hard at the time to make some link between these. Things got worse when I was 33 and that led my diagnosis after inflammation in both my feet.