1. What is Adrenal Fatigue? Adrenal fatigue is a condition in which the adrenal glands function at a sub-optimal level when patients are at rest, under stress, or in response to consistent, intermittent, or sporadic demands. The adrenal glands are two small glands that sit over the kidneys and are responsible for secreting over 50 different hormones—including epinephrine, cortisol, progesterone, DHEA, estrogen, and testosterone. Over the past century, adrenal fatigue has been recognized as Non-Addison’s hypoadrenia, subclinical hypoadrenia, neurasthenia, adrenal neurasthenia, and adrenal apathy.