Thanks, soz, k & dag for your concern about my wretched wrist!
I have no idea what the cause is but it's been quite swollen & very painful.
I went to the doctor last night who prescribed an Xray (which I just had tonight). He (the doctor) told me (after much prompting from me) that the cause could be anything from a sprain, arthritis, gout

, etc, etc, etc ...
In the meantime I've been taking many Panadols & wincing a lot.