As Mrs D said - definatey report to doc - could be many issues.... my "theme" song is "Dizzy" - I get dizzy from my heart med that I have to take for arrythmias so have to get up slow - but since PN sometimes get very dizzy just movimg - and the docs say its an autonomic dysfuction of my heart due to neuropathy - my blood pressure doesnt adjust when I get up and stays low - thus the dizziness and possible fainting.... they sent me to cardiologist for a tilt table - who after just doing the lay down, sit, stand blood pressure testing and seeimg no change in pressure (it should adust to your altititude) - said he didnt need to put me thruogh the tilt table - he knew I'd pass out and throw up - and he didnt want to subject me to that.... instead just be very careful moving...
But again, could be many many issues.... and important to try to figure out what!