Cortisol, also known as hydrocortisone, is a steroid hormone or glucocorticoid produced by the adrenal gland. It is released in response to stress, and high levels of cortisol lead to high blood pressure, weight gain and other deleterious manifestiations. On the other hand, low levels reflect chronic stress and cause adrenal fatigue, poor immunity, fatigue and depression. Cortisol’s primary functions are to increase blood sugar, suppress the immune system, and aid in fat, protein and carbohydrate metabolism. It also decreases bone formation.