The adrenals are located at the top of each kidney, and produce hormones that help the body control blood sugar, burn protein and fat, react to stressors like a major illness or injury, and regulate blood pressure. Two of the most important adrenal hormones are cortisol and aldosterone.  Adrenal insufficiency occurs when the adrenal glands don’t make enough cortisol, and sometimes, aldosterone. Symptoms include fatigue, muscle weakness, decreased appetite, and weight loss.