The adrenal glands are small glands that are located on top of each kidney. They produce and release essential hormones into the body that affect metabolism, blood pressure, the immune system, sex drive, and the body’s response to stress. One of the most important functions of the adrenal gland is the fight-or-flight response. When a person is stressed or frightened, the adrenal gland releases a flood of hormones, such as adrenaline and cortisol. These hormones increase the heart rate, elevate blood pressure, boost energy supplies, sharpen concentration and slow down other body processes so the body can run from or fight a threat.
Too much of a stress response is a bad thing, though. Too much exposure to elevated hormones from the adrenal gland can cause anxiety, depression, digestive problems, headaches, heart disease, sleep problems, weight gain and memory and concentration impairment, according to the Mayo Clinic.