As if out of nowhere I woke up one morning with an incredibly painful and stiff finger. It felt a bit like a jammed finger except that I could slowly bend it to a closed position (with pain), such that it would be fully mobile afterwards with some background pain for the rest of the day. Next morning same thing. Incredibly stiff and painful, requiring a slow process of "remobilizing" it.
I have additionally noticed a single small cluster of clearish/flesh-colored bumps on one side of the same finger in between the two outer joints. They don't hurt and they might not even be related, but it is curious that the only hurting finger has them.
I did some uncharacteristicly harsh work with my hands recently (hours and hours of gardening and heavy squeezy to cut down shrubs), but I did not notice the problem immediately after this work. More like a few days to a week after, so this may or may not be correlated as well.