I keep getting a headache when I go longboarding any ideas?

I keep getting a headache when I go longboarding any ideas?
Every single time I go down a hill I get a headache. Even if I'm just standing, doing a chill run, I still get a headache. Then if I do try a speed crouch I get a headache, but just as I'm going into the crouch, not as I'm standing up. Also the headache is from ear to ear and back to about the middle of my head, I only get it while longboarding, WEIRD! Does anyone know what is going on?

I too felt the same, but when I got used to it I enjoyed to the maixmum. Practice makes a man perfect.