The adrenal glands rest on top of the kidneys.  There are two parts: the cortex and the medulla.  The inner part, the medulla, produces the hormones norepinephrine and epinephrine, which regulate the "fight or flight" response in your body to stressful events.  The outer part of the adrenals, the cortex, produces the hormones cortisol, DHEA, estrogen & testosterone, which affect blood pressure, glucose levels, growth and some sexual characteristics.  The adrenals modulate the function of every gland, organ & tissue in your body to maintain a condition of homeostasis (i.e., equilibrium).  Constant stress, as well as aging, lowers our adrenal function resulting in depression, chronic infections, fatigue, food cravings, hypoglycemia and weight gain.