every time my son stands up or sits up, he gets a throbbing headache in the front/top of his head. It goes away w/in 15 minutes if he lays down. He had spinal fusion surgery 31 days ago, but blood counts normal when left hospital. was given 4 units of blood during surgery; 2 of which were his. these headaches do not respond to pain medication. he's off medicine from surgery for 1-2 days. only takes aleve or advil. no signs of spinal fluid. surgeon said they weren't in that area to cause problems. & these headaches didn't start till 5 days ago. thought m/b caused by low blood pressure caused by valium, flexeril or lortab he'd been taking since surgery. but they're continuing 2 days after off of everything. ,we've been giving fluids, salt, etc. for LBP.