I too have Sjogren's and have been experiencing "heat flashes". It comes on suddenly with sweating all over, slight nausea, and slight panicky feeling. I'm 67 and have had a hysterectomy. It only lasts few minutes then I can feel really cold. My PCP said I shouldn't be having hot flashes. My Tsh is normal. She also took me off Cymbalta and switched me to prestiq. I haven't been able to find much research on dysautonomia with sjogren's in the literature. If anyone has seen this in the literature I would love to read more and take it to my rheumatologist.