For over a year I have been trying to find out what causes these episodes at night. I have had stress tests to make sure it's not my heart, and it's not. It starts with a wave of dizziness, even though I'm laying down, then I get hot flash, then nausea. I breath through it, but it comes in waves. It eventually makes me shake as if I"m really cold, but I'm not. I scares me sometimes and I get up and sleep upright on the couch. I am constantly constipated, no matter what i eat. Milk of Mag gives me some relief but the constipation just returns. I eat fibre all the time, no change. I am trying to watch what I eat to see if the episodes are related to that, but can't find a connection. I am taking Zumba classes and each of those nights I had these episodes. Has anyoone else experienced this?