Understanding Cortisol (AM): Normal vs Optimal Ranges

?What is Cortisol (AM)?

Morning cortisol (collected at 8 AM) captures the cortisol awakening response (CAR) — the peak of the daily diurnal cortisol rhythm. Cortisol is a glucocorticoid stress hormone produced by the adrenal cortex in response to ACTH from the pituitary. It regulates metabolism, immune function, blood pressure, and the stress response.

!Why It Matters

Morning cortisol is the gold-standard screening test for adrenal insufficiency (Addison's disease) and Cushing's syndrome. Very low morning cortisol suggests adrenal failure, while very high levels may indicate Cushing's or extreme physiological stress. Chronically elevated cortisol (from psychological stress) promotes abdominal obesity, insulin resistance, and immune suppression.

Reference Ranges

Lab normal ranges may vary between laboratories. Optimal and longevity targets are based on research literature and should be interpreted with your physician.

Symptoms of Imbalance

• Low cortisol: profound fatigue, dizziness on standing, nausea, weight loss, craving salt
• High cortisol: weight gain (especially abdominal), easy bruising, stretch marks, high blood pressure

How to Improve Your Levels

• 1Practise stress reduction: meditation, breathing exercises, yoga
• 2Prioritise quality sleep — sleep deprivation drives cortisol elevation
• 3Regular moderate exercise (excessive endurance training can raise cortisol)
• 4Adaptogens like ashwagandha and rhodiola may modestly reduce cortisol under stress
• 5If adrenal insufficiency is suspected, seek urgent specialist evaluation

When to Test

Always at 8–9 AM for meaningful interpretation; repeat in suspected adrenal pathology; baseline in chronic fatigue workup.

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