Left index finger has been stiff, sore and painful for 3 days. Is this arthritis or maybe sleeping on arm wrong? Was wollen at first on waking.

Trigger finger . Is it common source of pain and stiffness which often seems to be worse in the morning. Arthritis can also close early morning stiffness but less, then someone younger Less it’s inflammatory or infectious

Varies. There are multiple potential causes including infectious, inflammatory, and arthritic conditions. Don’t hesitate to be seen for it, especially if you develop redness and increased temperature.