I have Sjogren's Syndrome which causes dryness all over the body. I was diagnosed a year ago, but. I have had extreme POIS for 19 years and I am 36 now. I wondering if they are related. Also I have Autonomic nerve damage which causes orthostatic hypotension and Postural Orthostatic Tachycardia which means my heart rate rise more than 30 beats from laying to standing mine actually rises about 55 beats from 85 to 140 beats/min. Been bed ridden and home bound for 3 years now and it has ruined my life essentially.