I have a twicthing vein/artery in my hand. it occasionally hurts. i took a video to show it more clearly: http://vimeo.com/34617295 should i worry?

Small Aneurysm?: I saw the video. Most likely is of no concern but if this is a pulsatile artery is very superficial and any trauma can make it bleed fast and easily. Have you or your family had aneurysms? I would check with a vascular surgeon if they thing it warrants to get at least a doppler ultrasound. Other remote possibility is a av malformation.

Maybe not: It appears, though i can't tell for sure, be just be a dilated vien. It could easily be excised but preoperative test may better further delineate the scope of the problem.

I would check it out: Your video is very good! you are clearly seeing a pulsation from an artery. There is a small vein that is near it but it doesn't appear to be connected. It could be nothing but you certainly don't want to be sitting on something worrisome. An ultrasound would be helpful in getting more information easily and quickly. I would see a vascular surgeon or a hand surgeon.