Muffled hearing on standing up after prolonged sitting. SpO2 drops momentarily when lying down in bed, and low SpO2 on plane.. (Previous DVT/PE) in Dysautonomia Discussion Posted October 29, 2019 · Report reply I'm 47yo, 6'1" 260lbs. I was tested for Orthostatic Hypotension last year in Houston,TX with tilt table, etc, and the doctor said I didn't have it. I've had TWO past DVT's/PE's and now wear compression stockings and take Xarelto daily. If I drive for two hours or sit for awhile, it can sometimes trigger this "muffled" hearing I get when standing. It sounds like my hearing pulses in and out repeatedly, and I feel a little off. It happened today when I got out of my car after a 2 hour drive. I did not have my compression stockings on. Also every night when I go to sleep, I turn on my CPAP machine and lay down. I used two different oximeters, and they always record my SpO2 going down to around 89% and then back up to 94-95% after a minute. Because of my two past DVT/PE's, my normal SpO2 is around only 94-95% max. I took a flight earlier in the year and started feeling light headed during the flight and very flush/warm in my face. I measured my SpO2 multiple times, and it was dropping as low as 85% at times, and then back to the low 90's. To get it to 95%, I had to take deep breaths. This happened on my return flight too. And I was wearing compression stockings. I've talked to my hematologist, cardiologist, and pulmonologist. They all ran tests on my heart and lungs and didn't find anything wrong. This is a little frustrating, since I'm planning another flight soon, and am worried my SpO2 will drop to the 80's again. But my doctors don't seem to have any answers. I'm wondering if this is orthostatic hypotension, or just related to my past DVT's that may have messed up the valves in my leg veins. Has anyone with dysautonomia had symptoms like this?