It’s awful! I didn’t feel it until I’d been at work for an hour, I got a car up on the lift, and I went under it to inspect it. I looked up, everything started spinning, and I had to grab the car and the lift to keep my footing while I completely lost my sense of balance. I researched some exercises, and thankfully it has mostly subsided; it was rough until lunch time and then I felt better, but I did get a little right after I got home. I had several “episodes” in those 3 hours-ish where I was fine with my head level, but incline or turn and tilt caused balance loss and spinning. Sitting down for a couple minutes helped. I didn’t sleep well last night, and I didn’t feel well in the morning, but at that time I figured I just had one beer too many the previous night. Taking it easy tonight, going to get lots of sleep.
I’ve been doing situps and back extensions in the mornings (I skipped today because I didn’t feel well) so I’d think I’d notice vertigo pretty quickly. OTOH, maybe skipping today screwed me up?