There is a vein on top of my right arm near my wrist that is really bizarre. any ideas to what is wrong?

Ok since about last week my hand has been bothering me, especially with movement (aka opening and closing it) I don't recall injuring it, but my job is physically demanding at times. Anyway, most of my veins on my right hand look larger and more raised than my left hand. but what is more concerning to me is a large vein on the top left side of my right arm that begins to bulge out about 2 inches from my wrist. To the touch its super squishy, slightly dark and raised when laying normally. but If I rotate my wrist to the right it indents. It feels tender to the touch and I have a feeling its the source of my hand pain. Any ideas as to what it could be? I'd hope everyone can spare me the "go to the doctor if you're so concerned" comments.... i do plan on going if I don't see a change, but I'm just trying to get a little insight.... thanks! Oh, and I'm female in my late 20's.