The normal diurnal variation of cortisol shows higher levels in the morning than in the evening. This finding is:

The normal diurnal variation of cortisol shows higher levels in the morning than in the evening. This finding is:

• A. A normal finding
• B. Cushing syndrome
• C. Addison disease
• D. Hypopituitarism

Answer: (A)

Cortisol follows a daily circadian rhythm driven by the hypothalamic-pituitary-adrenal axis: levels rise in the early morning to help wakefulness and energy, then decline toward the evening. Seeing higher cortisol in the morning than in the evening fits this normal pattern. In conditions like Cushing syndrome, cortisol is often elevated overall with a reduced or absent nocturnal dip, while Addison disease and hypopituitarism can lower cortisol and disrupt or blunt the rhythm. So this diurnal variation is a normal finding.

Cortisol follows a daily circadian rhythm driven by the hypothalamic-pituitary-adrenal axis: levels rise in the early morning to help wakefulness and energy, then decline toward the evening. Seeing higher cortisol in the morning than in the evening fits this normal pattern. In conditions like Cushing syndrome, cortisol is often elevated overall with a reduced or absent nocturnal dip, while Addison disease and hypopituitarism can lower cortisol and disrupt or blunt the rhythm. So this diurnal variation is a normal finding.