That was something that I wasn’t taught in school when it came to blood donor deferral.

All I do is type blood, crossmatch it, and issue it when it comes to blood banking. You can only donate blood autotologously which is like donating snow to Eskimos. It is the JAK2 mutation that causes PV. PV is definitely listed under a myeloproliferative disorder like CML. Fun fact PV can turn into acute leukemia.
Ya I know about the leukemia...but oh well I've lived a good life so if I gotta go then I gotta go.
Here is another fun fact. I spent two years restricted to my bed and a wheelchair because of CFS(chronic fatigue). I was very active in the outdoors so this pretty much devastated me. Lucky for me my immediate family only lived two hours away so they were able to come help me, by driving to appointments, mowing my lawn, buying my food, and rearranging my room so my computer was a couple of feet from my bed....so I could shitpost here
I went through so many tests that everybody knows my name at the local hospital. It wasn't until my shins turned bright red and my hams/feet swelled up that they figured out what I had. When they drained me the first time 1000ml within 24hours my CFS disappeared. It was like a light switch. Though I still have some tiredness and shortness of breath it is no where near what I had. I went through a couple of weeks of physical therapy so I could walk again.
They have a standard procedure if I get admitted to the hospital.
1) they put me on an antibiotic iv.
2) they ultra-sound my legs looking for blood clots.
3) they give me two or three shots in the stomach of blood thinner.
They also gave me a new antibiotic shot which lasts for 30 days. I don't remember what it is called, but I was like...okay..nice.
I suppose that is so they don't get sued, as they are looking for blood clots, cellulitis, and sepsis.
They also quarantine me for MRSA if I have any type of wound on my shins, because they can't tell until they get the results back.
Nice yellow outfits there nurse

Plus I no longer get a plate for food, just a paper plate and plastic fork/knife/spoon that they toss.
So that is why I say when people say they have CFS doctors should listen.