Now I know no one can tell me exactly what's wrong, and that I should go and get an xray, but I just can't do that since if they wanted to put it in a splint or cast or something I wouldn't be able to write, and I'm in the midst of a great deal of important exams. Please, just do your best to decide what I've most likely done.

Yesterday I punched one of those machines that measures your score depending on how hard you punch, but my wrist wasn't quite straight as I did it so my hand bend downwards in the follow-through. It hurt at the time, a fair bit but it wasn't excruciating. Today it's been hurting quite frequently but only in specific positions. It doesn't continuously and, for example, I just lifted a 50 litre bag of compost and it didn't hurt at all.

The positions that cause me quite a lot of pain are if I clench my fist at the angle I hit the machine, or push against the back of my hand at a downward angle. It also hurts if I bend my middle finger to the side. There's no swelling and I can rotate my hand through 360 degrees without any pain.

Thanks very much for your time.