My mother was diagnosed hypo a few years ago. She collapsed three times and ended up in ambulance to A&E. I noticed that prior to each collapse she'd gone from sitting to standing suddenly, once in church, another time in a waiting room and at a friends house, each time she'd stood up, then fallen back down. When I asked if there was a connection they monitored her and found she had low blood pressure when resting.
Whenever she'd arrived at hospital her BP seemed normal but because it was being pushed up by the stress of what had just happened to her.
They stopped her tablet for high blood pressure (she'd been on them for years), monitored her for a week then prescribed something to raise her BP which seemed to work. She never collapsed again, I checked her blood pressure twice a day and it was always within limits so the problem went away.
K