I believe adrenal fatigue is a real thing... at least in part because I see it walk into my office on a regular basis. I use Adrenal Salivary Index (ASI) testing to analyze the pattern of cortisol and related hormones such as insulin and DHEA and treat with dietary changes and supplements accordingly... although that is the easy part of what I do.
The thing about the adrenals is that they are almost never the problem, per say. The adrenals, like the immune system, is a reactionary system in the body- they respond to stressors from your environment and adapt however they are able to. It's not that they are "being bad" or "acting up"- they're just trying to keep you alive and reflecting the stimuli they are given. Perhaps we should start calling pathology reactive physiology. The true art in helping the adrenal fatigued patient is in untangling the things that stressed the adrenals in the first place.
This is largely because adrenal hormones, like all hormones, have about a million different actions and affect every cell of the body. Cortisol, the most famous of the adrenal hormones, has profound impacts on the immune system, the circadian rhythm, insulin and blood sugar control, memory, gastrointestinal tract, thyroid, skin, metabolism, and sex hormones. Pathways and enzymes are shared amongst the making of estrogen, testosterone, cortisol, DHEA, progesterone, and vitamin D, so you really can't affect one in isolation of the others. This is what makes hormones so cool and so very tricky- they have the ability to affect everything in the body.
Honestly, I treat the adrenal fatigued patient as I would any other functional medicine patient in my office. I conduct a thorough history and examination, blood work and specialty lab testing in order to get a grasp on what is happening to the patient's body. I try to trace the threads of the web back to the spider from whence they came and treat the body as holistically and naturally as possible. The difference with adrenal fatigue is that once I know that the adrenals are compromised, I may add adrenal supportive herbs, supplements, and targeted lifestyle advice to the patient's treatment plan.
If you or somebody you know is interested in working with a functional medicine doctor please call my office at (919) 238-4094 and see if we are the right fit for you. Infinity Holistic Healthcare is located in Chapel Hill, North Carolina, part of the Raleigh-Durham "triangle" area.