Understanding Sudden Onset Headaches: Causes & Relief

Question
Hello there.  I am a 37 year old mother of three, 140 lbs, 5'7" and have had a certain type of headache for many years now.  It is absolutely excruciating and happens if I stand up from a sitting position too quickly or if I talk too loudly for a sustained period of time or my breathing is out of wack.  When  I stand up quickly, there is a 'rush' to my head and a slight delay and then an absolutely excruciating headache.  I control it with slow, deep breaths.  My heart will also race very quickly when this happens.  If I am speaking in a loud/crowded area for a sustained period of time, my headeache will come on (the pressure and pain is incredibly intense) and I will also really run out of breath.  I will also become lightheaded and weak at times.  I've had my blood pressure checked a million times and it's always normal.  My doctor is now sending me for a Tilt Table Test?  I'm worried it might be restricted blood vessels.  Is there any other possibilities I should consider and other tests that should be taken? (thyroid? heart? -- I'm really concerned with a restriction of blood flow in my head and possible long term effects if not diagnosed).

Thank you very, very much for your expertise.

C. Schroeder

Answer
I think your  doc is thinking what I think... a hormone producing tumor that responds to little drops in BP... sends out hormones that spike the blood pressure.  If you haven't had it, you need to have a 24 hour urine for VMA and metanephrines.  They will know what that is...