I'm gonna give my two cents on the matter since I have a small history of polycythemia...
It's not a real cancer, it's more a 'blood dysfunction'. Your blood produces too many red blood cells. Since it's not a real cancer, there's another form of it called Secondary Polycythemia. This means the cause is from another problem and it's secondary... This is what I had, before doctors found my kidney cancer and removed it and part of one of my kidneys... After surgery my blood tests returned to normal thankfully...
Here are other causes of secondary polycythemia:
The most common causes of secondary polycythemia are
Other common causes include:
So here's what I think is going on. Boogie, being a useless fat fuck, possibly has heart disease, possibly sleep apnea since it happens much more often with morbidly obese people, uses diuretics due to heart disease, and possibly has other things going on. His terrible diet habits basically gave him secondary polycythemia and he's been using it for sympathy points.