thank you for answering my question. I seem to find out more from my other doctors than my hematologist. He says my fatigue and shortness of breath are not related to my PV & ET. He is the only doctor that comes to Pahrump, NV. Las Vegas is 60 to 70 miles away depending where I have to go. There are no specialists in Nevada. My choices are Florida, or Texas and don't know if my insurance would approve going out of the area. Thanks again for the info

That is what is called secondary Polycythemia, when you do not have a mpn but something that causes the Polycythemia

I am post ET MF. I was diagnosed with sleep apnea a few years ago. I was seeing a pulmonologist and I tried the cpap for a while. I hated it so eventually I stopped. My pulmonologist never said it contributed to my MF.

Rita, all I can tell you is from personal account. I have tried to find scientific studies on the subject but I was not able to find anything. This is because my wife, the patient with Jak2 mutation, had sleep apnea which I would hear during the night. After being treated with Jakafi, I don't hear apnea any longer.
So is it possible that sleep apnea can encourage the body to make more red blood cells since pauses in breathing doesn't bring as much oxygen into the body and the body then makes more red blood cells in order to get more oxygen to the cells of the body? Maybe.
Or is it possible that the excess red blood cells in PV patients brings too much oxygen into the body and breathing then slows down (causing apnea) in order to normalize oxygen intake during the night when less oxygen is needed by the body? Maybe.
I have thought about this a long time because of my wife's condition but haven't found supporting answers.
All I can tell you is that since her PV is under control with newer medication, it appears to me that her sleep apnea has corrected. She is also a type 1 diabetic and wears a continuous glucose monitor and an insulin pump, and we don't want to add to her apparatuses with a CPAP machine.
Maybe some of our more knowledgeable members on this site can contribute more scientific information on this subject.