Cortisol (皮質醇) is often referred to as the “stress hormone.”

Cortisol levels follow a daily cycle, peaking about 30–45 minutes after waking (the “cortisol awakening response”) and gradually declining throughout the day.

Functions

• Increases blood sugar through gluconeogenesis
• Aids in metabolism of fat, protein, and carbohydrates
• Helps regulate blood pressure

Stress Response

During periods of acute stress, cortisol levels rise rapidly, preparing the body for “fight or flight.” Chronic stress can lead to persistently high cortisol, which is linked to negative health outcomes (e.g., impaired cognition, suppressed immunity, increased abdominal fat).