vascular endothelial growth factor. Certain inflammatory responses to things can cause levels to drop which can lead to capillary hypoperfusion, lowered vo2max, and thus lowered energy, muscle soreness/spasms, and shortness of breath. It can tell you whether or not that is whats happening, good fork in the road if you will. If it is, further testing might help narrow down where its coming from, or at least rule out other things. If its not that bad and possibly getting better as you get things straightened out, its likely a part of the fatigue that comes with chronic inflammation and its after effects. Sometimes it takes a while to come around. When you can handle it, if its a case of post infection chronic fatigue, short medium-intensity non aerobic exercise can help it. If it hangs out for too long, suspect you’ve got other stuff going on that needs some attention.