[cpncrunch]

Just to add to the above: the reason that "adrenal fatigue" was coined is because stress does affect the adrenal glands: initially it causes increased release of cortisol and an increase in size in the glands, but chronic stress can result in hypofunction of the HPA axis, resulting in lower cortisol and sometimes shrinking of the adrenal glands. Whether chronic stress results in fatigue and low cortisol depends on the nature of the stressor, the time since onset, personality factors, etc.

http://dx.doi.org/10.1037/0033-2909.133.1.25

Unfortunately the "adrenal fatigue" crowd have taken this little bit of science and completely mangled it, blaming the adrenal glands themselves and pushing dubious supplements that have no scientific basis.