I was checked for that today. I have a tender swollen spot in the bend of my arm. It is where a nurse a few days ago poked me to try and draw blood. She never did find the vein. Now it feels like nerve damage. I have shooting pains that go from there and up my arm. When I move my arm a certain way. It really scared me so I got an ultra sound of my whole arm and they found no clots. Thank God! They say it's rare but still I was worried and now wondering what is really going on in the arm. No sign of infection or clot. What is it? How long will I have swelling and shooting pains?