For the past three months I have been doing physio exercises for a knee issue. They are definitely helping.
The first three exercises are all done lying down - I don't know the proper name for each exercise, but they are - lying on my back and arching my back, with my heels down, rather than my feet being flat on the floor x 10, lying on my left side and raising my right leg, with my foot tilted so that my heel is higher than my toes x 10, lying on my right side and raising my left leg, again with my foot tilted x 10.
On three occasions in the three months, when I rolled from left side to right, the world started spinning, I felt instantly nauseous, and I came out in a cold sweat. I staggered to the toilet to throw up, and I was clammy.
One minute I'm fine, then BAM! It then takes hours to stop feeling nauseous and dizzy. The rest of the day is a write-off.
The first time it happened I'd had a very busy day and the first opportunity to do the exercises came after dinner. I assumed the problem was that I'd done them too soon after eating. But that doesn't explain the next two times.
The third time was yesterday; I'm going to skip the exercises today because I have to catch up on work I didn't get done yesterday, and I'm still feeling a bit "off"
What might be causing this?