Cortisol is a vital steroid hormone produced primarily by the adrenal glands, playing a critical role in managing stress responses, metabolism, immune function, and inflammation. Often referred to as the "stress hormone," cortisol is released in response to stressors, helping the body adapt by increasing energy availability through raising blood glucose levels, mobilizing fats and proteins for fuel, and enhancing alertness and focus. It also regulates immune responses and inflammation, maintaining a balance to prevent excessive immune reactions. However, chronic elevations of cortisol due to prolonged stress can lead to negative health outcomes, such as impaired cognitive function, increased fat storage—particularly in the abdominal area, immune suppression, hypertension, and metabolic disturbances. Clinically, cortisol and its synthetic forms (glucocorticoids) are utilized to treat inflammatory and autoimmune disorders, allergies, and adrenal insufficiencies. Ongoing research continues to explore cortisol's complex interactions within the body, seeking to optimize therapeutic applications, manage stress-related disorders effectively, and enhance overall metabolic and physiological health.