I have a vein in my arm thats sticking out and it hurts when pressed its like a little ball in my vein what can ths be?

Vein irritation: Did you have IV or blood draw sometime recently? Injury? It sounds like a vein irritation or inflammation called thrombophlebitis? See your family doctor.

Clotted vein?: A bulging in an arm vein can be normal or due to an underlying problem. Some veins may bulge especially if the bulging is in an area of a valve. Painful bulging areas especially if hard may be due to a clot in the vein. You should see a vein specialist for an evaluation.