It’s your body’s main stress hormone. It works with certain parts of your brain to control your mood, motivation, and fear. Your adrenal glands make cortisol. It’s best known for helping fuel your body’s “fight-or-flight” instinct in a crisis, but cortisol plays an important role in a number of things your body does. For example, it:
– Manages how your body uses carbohydrates, fats, and proteins.
– Keeps inflammation down.
– Regulates your blood pressure
– Increases your blood sugar (glucose)
– Controls your sleep/wake cycle.
– Boosts energy so you can handle stress and restores balance afterwards.
Your hypothalamus and pituitary gland — both located in your brain — can sense if your blood contains the right level of cortisol. If the level is too low, your brain adjusts the amount of hormones it makes. Your adrenal glands pick up on these signals. Then, they fine-tune the amount of cortisol they release.
Cortisol receptors — which are in most cells in your body — receive and use the hormone in different ways. Your needs will differ from day to day. For instance, when your body is on high alert, cortisol can alter or shut down functions that get in the way. These might include your digestive or reproductive systems, your immune system, or even your growth processes.
Source : https://www.webmd.com/a-to-z-guides/what-is-cortisol
– High cortisol : see Cushing syndrome
– Low cortisol: see Adrenal insufficiency