Interpret Your Cortisol Results
Enter your Cortisol value below and get an instant, free AI interpretation — a plain-English explanation checked against WHO/IFCC reference ranges.
Medical Disclaimer
This AI-generated interpretation is for educational purposes only and does not constitute medical advice, diagnosis, or treatment. Results may vary based on individual health factors not captured here.
Always consult a qualified healthcare professional before making any health decisions. Read full disclaimer →
Cortisol Normal Ranges
Cortisol is the primary glucocorticoid hormone produced by the adrenal cortex under the influence of ACTH from the pituitary gland.
| Age Group | Reference Range | Unit | Notes |
|---|---|---|---|
| Adults (18–64) | 6 – 23 | µg/dL | Morning (8 AM) |
| Adults (18–64) | 2 – 12 | µg/dL | Afternoon (4 PM) |
Also reported in: nmol/L.
Critical (Panic) Values
Critical Low: < 2 µg/dL. Values outside these limits require immediate clinical attention.
Why Doctors Order the Cortisol Test
Cortisol measurement is essential for diagnosing Cushing's syndrome (cortisol excess — from adrenal tumor, pituitary tumor/Cushing's disease, or ectopic ACTH) and Addison's disease (primary adrenal insufficiency).
How to Enter Your Cortisol Result
Cortisol can be reported in µg/dL or nmol/L. Choose the unit printed next to your result on the lab report so it is compared with the matching reference range.
What a Low or High Cortisol Can Be Associated With
Below the reference range
- Addison's disease (primary adrenal insufficiency — autoimmune, TB, metastases)
- Secondary adrenal insufficiency (pituitary ACTH deficiency)
- Abrupt withdrawal of long-term corticosteroid therapy
- Waterhouse-Friderichsen syndrome (adrenal hemorrhage in meningococcal sepsis)
Above the reference range
- Cushing's disease (pituitary ACTH-secreting tumor — most common cause)
- Adrenal adenoma or carcinoma
- Ectopic ACTH secretion (small cell lung cancer)
- Exogenous corticosteroid therapy (most common overall cause of high cortisol effect)
- Physical stress (surgery, illness, trauma)
This interpreter flags a result at or below 2 µg/dL as a critical value. Results that extreme are uncommon — contact your doctor promptly, and seek urgent medical care if you feel unwell.
These are common associations, not a diagnosis. A single result is read alongside your symptoms, history and other tests — discuss it with your doctor.
What Can Change Your Cortisol Result
Before you read too much into a result, consider whether any of these applied:
- Time of day (mandatory consideration — diurnal variation is large)
- Exogenous corticosteroids (raise cortisol, including inhaled and topical steroids)
- Physical illness and surgery (markedly raise cortisol)
- CBG (cortisol-binding globulin): elevated in pregnancy and oral contraceptive use (raises total cortisol without raising free cortisol)
Preparing for the test: For morning cortisol: draw at 7–9 AM. For afternoon cortisol: draw at 3–5 PM.
Symptoms That Often Prompt Cortisol Testing
- High cortisol (Cushing's): central obesity, "moon face," "buffalo hump," purple striae, hypertension, diabetes, easy bruising, muscle weakness, osteoporosis
- Low cortisol (Addison's): fatigue, weight loss, nausea, skin hyperpigmentation, low blood pressure, salt craving, low sodium, high potassium
Want the full clinical guide to Cortisol?
Reference ranges, causes, symptoms, preparation, and FAQs.