It fills with fluid the next day and the pain goes away. It is caused by the pressure of my body against the board, what is this?

this is a condition called stimmulate noctosis! it is , as you said, the filling of the testicles with fluid! l suggest you refrain from using a longboard as constant pressure will make the testicle useless and lame! so get a shortboard or lose a nut!!!! Yours Dr. Carew!

What are you wearing when you surf. Maybe you need something that gives ''the boys'' a little more freedom to move out of the way so you're not laying on them. If you are prone to this type of injury l do not see that riding a short board would have a different result.

Tuck and tape. Stop laying on your nuts. Buy bigger board shorts.