Why is it that every time my hunting buddies and I get together and have a crawfish boil I wake up with a pounding headache the next morning?

too many crawfish, not enough Bud!

Have your blood pressure checked. To much salt or to much beer, or a combination of the 2.

Hydration sir, hydration... that oughta fix the problem.

I wouldnt worry about it too much unless you wake up with that pounding headache and a sore butt with an open bottle of vasaline next to you. LOL Just kidding, you need to drink more water.

im a paramedic and you need to think about if your tired as well. The first sign of dehidrationis fatigue and the a headache! If your drinkin that will def contriubute to it.I think all of these other guys are right..... DRINK MORE WATER!!!!