What Is Cortisol?
Think of cortisol as nature’s built-in alarm system. 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 — triangle-shaped organs at the top of your kidneys — make cortisol. Cortisol plays an important role in several 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 afterward

How Does It Work?
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.

Sometimes, your cortisol levels can get out of whack.

Too Much Stress
After the pressure or danger has passed, your cortisol level should calm down. Your heart, blood pressure, and other body systems will get back to normal.
But what if you’re under constant stress and the alarm button stays on?
It can derail your body’s most important functions. It can also lead to a number of health problems, including:
• Anxiety and depression
• Headaches
• Heart disease
• Memory and concentration problems
• Problems with digestion
• Trouble sleeping
• Weight gain

Too Much Cortisol
A nodule (mass) in your adrenal gland or a tumor in the brain’s pituitary gland can trigger your body to make too much cortisol. This can cause a condition called Cushing syndrome. It can lead to rapid weight gain, skin that bruises easily, muscle weakness, diabetes, and many other health

Too Little Cortisol
If your body doesn’t make enough of this hormone, you have a condition doctors call Addison’s
disease. Usually, the symptoms appear over time. They include:
• Changes in your skin, like darkening on scars and in skin folds
• Being tired all the time
• Muscle weakness that grows worse
• Diarrhea, nausea, and vomiting
• Loss of appetite and weight
• Low blood pressure