What is this...a popped vein maybe?

On the bony part of my left ankle (kind of like the knuckle of the ankle) the skin is red, and feels a little rough...it's a noticable difference between that one and my other ankle. The vein also feels a little more projected; and i kinda hurts when i'm walking sometimes. I jump on my trampoline a lot, and i have sprained my ankle many times, but not recently. Is this most likely a popped vein or a bruise? If it is a popped vein, what do I do?