2 times in 3 months I have experinced the same issue. Suddenly, with no injury or extreme use, I begin having pain from top of wrist back along center line. Feels like pulled muscle. Within hours it begins to swell slightly, the wrist hurts terribly. Cannot move fingers without agony. If the fingers are pressed down lightly the pain increases. If the fingers are lifted slightly (using the other hand) the pain decreases slightly. Within 1-2 days it goes away. Vein leaking causing pressure?