I was at my son's football game yesterday and I stood up to cheer when they scored. I felt a rush to my head and a sudden stabbing pain in my head followed by slowing of perception and then I blacked out. It was only for a second and I was able to sit again without falling. I had a headache for about 15 minutes, but no other symptoms. I did notice some dizziness in the afternoon when I would stand suddently or change position. I checked my blood pressure at the local pharmacy and it was in the normal range. Today I ran in a half marathon and I took extra precautions to stay hydrated. despite my efforts I got another headache, but this one was persistent and is still with me hours later. I have rested, drank lots of water, ate, and I took 2 aleve then 4 hours later I tok 2 ibu9200 mg) but the headache lingers. It is difficult to judge whether i need to seek medical attention because of the precipitating events...the football game and the run. Any advice?