I'm in the beginning stages of an experiment of testing myself for POTS and NMH using an automatic blood pressure heart rate monitor and plan on putting the results in a blog. Preliminary evidence suggests that I have POTS but probably not NMH despite dizziness etc increasing somewhat when standing up. I thought about alternative explanations for reduced blood flow to the brain despite presumably normal blood pressure. Several come to mind but one I'm considering now is chronically constricted neck arteries, because I often feel and hear a "whooshing" sound and pressure in the neck or head. It usually only becomes really noticeable under two circumstances: (1) when standing up, (2) transitory appearance at about 10-20 minutes after laying down to go to sleep. When standing up it may also be accompanied with the heart pounding sensation/sound in my head as well, but is not synonymous with it. I don't think massaging the neck has ever helped it. I wonder if a natural vasodilator would help. Does anyone have any experience with this symptom or treating it?