Wondering because along with the weird vertigo stuff my new found friend in migraine seems to include significant issues with sudden moderate to severe nausea sort of out of the blue. I would say that next to the exhaustion and disequilibrium that this is my BIGGEST problem. I’m doing so much better but was slammed with the stomach thing today. Wanted to commiserate but haven’t seen much on here about that issue.
dolfnlvr
I can totally commiserate with you! Nausea has been my ‘not-friend’ since Day 1 (06/11/2010)! None of the meds I’ve trialled have helped the ‘sudden-onset’ nausea - it depends on the weather, stress, ‘whatever’. I’ve given up trying to ‘pin’ a reason down. I will be happy to wave my ‘not-friend’ goodbye - one day. In the meantime I keep my ‘sea bands’ , a dry ‘gluten free’ cracker & water handy & distract my brain from my stomach!
Barb
It’s AWFUL!!! I swear, sometimes, if I didn’t know better, which btw I TOTALLY do, I’d swear I was in my first trimester of a pregnancy!!! Feeling fine then WHAMMO sick as a pup, nearly ready to vomit and down to the bones exhaustion. I remember the sensation well, but at least then there was a nice little prize in the Cracker Jack Box!!! This totally sucks!!! 
Me too, the nausea is at its worst for me when I have been exposed to a lot of bright lights or simply overdone it. Basically the nausea is bad when I’m feeling bad! X
I have sudden nausea too. Like everyone has said - it’s due to whatever symptom or symptoms kick in all of a sudden. I hate it. Crackers help - so do Pringles potato chips for some reason. Sitting down & closing my eyes can help - if wherever I am is quiet.
Sorry you have it too.
Molly