Cortisol

Cortisol is a hormone produced in the adrenal cortex that controls metabolism and the body's stress response. It regulates blood sugar levels, blood pressure, and influences the immune system. Cortisol typically follows a daily rhythm, with the highest levels in the morning and the lowest at night.

Permanently elevated cortisol levels can lead to weight gain, high blood pressure, sleep disturbances, and a weakened immune system. Too low levels indicate adrenal insufficiency and can be associated with fatigue, low blood pressure, and weakness.