Cortisol is one of the main hormones produced by the adrenal glands. It’s known as the stress hormone because it’s released during times of physical and emotional stress. It increases your heart rate, blood pressure, blood sugar, and breathing rate to give you a natural energy boost to take on whatever stressor is coming your way. That’s a good thing in the short term, but being chronically stressed can lead to high cortisol levels all the time, and that can have a serious impact on your health.