These hormones do many important things. For example, they help regulate fluid and salt levels in the body that affect blood volume and blood pressure. They also help the body react to stress and change. They cause a faster heart rate and boost other systems that help you to react quickly with a burst of energy when needed. Problems in the cortex or the medulla, then, can result in high blood pressure.

Cortisol levels are controlled by the pituitary gland, which is found at the base of the brain. The hypothalamus of the brain makes the corticotropin-releasing hormone (CRH). CRH tells the pituitary gland to release signals that control how much cortisol the adrenal glands make. The pituitary gland signal is called corticotropin or adrenocorticotropic hormone (ACTH).