Hormone Test

Cortisol Blood Test

Name: Cortisol Blood Test: Normal Range & High | HealthReview
Creator: Suman Konda
Published: 2026-07-05

Cortisol is the body's main stress hormone, produced by the adrenal glands. It regulates metabolism, blood pressure and immune function. Too much or too little causes serious conditions including Cushing syndrome and Addison disease.¹

Written by Suman Konda, Clinical Pharmacist · Based on peer-reviewed sources · Editorial policy · Not medical advice

Last reviewed and updated: 26 September 2026 · How we check our content

Quick answer

Cortisol is the main stress hormone, with a strong daily rhythm: 10-20 mcg/dL at 8am, falling below 3 by midnight. Persistently high cortisol means Cushing syndrome, most often from steroid medication. Low cortisol means adrenal insufficiency (Addison disease), and an adrenal crisis is a medical emergency. The time of the sample must always be recorded.

What is cortisol?

Cortisol is a steroid hormone produced by the adrenal cortex (the outer layer of the adrenal glands, which sit on top of the kidneys). It follows a strong diurnal (daily) rhythm: highest in the early morning (peaking around 8am) and lowest at midnight. Cortisol regulates: blood sugar, blood pressure, anti-inflammatory response, metabolism of fats/proteins/carbohydrates, and the body's response to stress. Cortisol testing must be interpreted carefully in the context of the time of day and clinical situation.

Cortisol normal range

Time	Normal Range (mcg/dL)	Notes
Morning (8am)	10 – 20	Peak; best time for testing
Afternoon (4pm)	3 – 10	Falls through the day
Evening / midnight	< 3	Near baseline
Random	Varies widely	Time of sample must be noted

Key points

Cortisol is the body's main stress hormone, made by the adrenal cortex; it regulates blood sugar, blood pressure, metabolism and the stress response.
It follows a strong daily rhythm, peaking around 8am and lowest at midnight, so the time of the sample must be recorded for the result to mean anything.
Persistently high cortisol is Cushing syndrome; the commonest cause is long-term steroid medication, then pituitary tumours (Cushing disease) and adrenal tumours.
Low cortisol is adrenal insufficiency: Addison disease when the adrenals are damaged (often autoimmune), or secondary when the pituitary makes too little ACTH, commonly after stopping long-term steroids.
An adrenal crisis, acute severe cortisol deficiency, is a medical emergency.
Confirmation usually needs specialised tests: 24-hour urine cortisol, late-night salivary cortisol, the dexamethasone suppression test, or the Synacthen stimulation test.

HIGH Cortisol: Cushing Syndrome

Persistently elevated cortisol is called Cushing syndrome. Causes: long-term steroid medication (most common), a pituitary tumour producing excess ACTH (Cushing disease), an adrenal tumour producing excess cortisol, or an ectopic ACTH-producing tumour (lung, pancreas). Symptoms: central obesity (round face and belly with thin limbs), purple stretch marks (striae), easy bruising, high blood pressure, high blood sugar, muscle weakness, depression, and in women, irregular periods and hirsutism. Diagnosis involves 24-hour urine cortisol, late-night salivary cortisol and a 1mg dexamethasone suppression test.

LOW Cortisol: Adrenal Insufficiency

Low cortisol is called adrenal insufficiency. Primary adrenal insufficiency (Addison disease) means the adrenal glands are damaged: causes include autoimmune destruction (most common in developed countries), tuberculosis, HIV/AIDS, cancer and bilateral adrenal haemorrhage. Secondary adrenal insufficiency means the pituitary is not producing enough ACTH, most commonly caused by sudden withdrawal of long-term steroid therapy. Symptoms: profound fatigue, weight loss, low blood pressure, salt craving, nausea, darkening of the skin (primary only). An adrenal crisis (acute severe cortisol deficiency) is a medical emergency.

Questions to ask your doctor

Is my cortisol taken at the right time of day?
Do I need a short Synacthen test (cortisol stimulation test)?
Should I have an ACTH level and a dexamethasone suppression test?
If I am on long-term steroids, how do I safely reduce them?
Do I need a pituitary or adrenal MRI/CT scan?

Morning cortisol vs evening vs suppression tests: how they compare

Cortisol is a moving target — it peaks at dawn and falls through the day. Each test catches it differently:

Test	What it measures	When it is ordered	Key limitation
Morning cortisol (8 am blood)	Cortisol at its daily peak	First screen for adrenal insufficiency or excess	One snapshot of a rhythmic hormone — timing errors ruin it
Evening / midnight cortisol	Cortisol when it should be lowest	Suspected Cushing's syndrome (loss of the night-time dip)	Stress, shift work and illness all flatten the rhythm
24-hour urinary free cortisol	Total cortisol excreted in a day	Confirming cortisol excess	Needs a complete 24-hour collection — incomplete jugs invalidate it
Dexamethasone suppression test	Whether cortisol suppresses as it should	Confirming Cushing's syndrome	Medicines (including the contraceptive pill) interfere — the drug list matters
ACTH	The pituitary signal driving cortisol	Alongside cortisol, to locate the problem (pituitary vs adrenal)	Fragile sample — needs special handling, or the result misleads

No single cortisol value diagnoses anything — endocrinologists read the pattern across timed tests.

Reading your report: what your doctor actually looks at

When a doctor opens a cortisol result, the number itself is only the starting point. Here is the checklist they run through — and the same checklist helps you read your own report calmly:

What time was the draw? Cortisol at 8 am and cortisol at 4 pm are different tests, interpretively. An “abnormal” value drawn at the wrong time is usually a timing error, not a disease.
Were you stressed? The blood draw itself, poor sleep, illness or pain all raise cortisol acutely. A high value on a stressful day often deserves a calm-day recheck.
What medicines do you take? Steroid creams, inhalers, joint injections and tablets all suppress or mimic cortisol — the full medicine list, including creams and inhalers, is essential context.
What is the pattern? A low morning cortisol suggests insufficiency; a high midnight cortisol suggests excess. One random daytime value, without the pattern, says little.
Was it confirmed? Cortisol excess and deficiency are both confirmed with dynamic testing (suppression or stimulation tests), never on a single blood value. Ask what the confirmatory step is.

Cortisol results are among the most context-dependent in medicine — time of day, stress and medicines can each outweigh the disease signal. Discuss the full picture with your endocrinologist.

Cortisol test price in India: typical bands across major lab chains

A single cortisol blood test is moderately priced; the dynamic confirmatory tests cost more. Typical list-price bands for the blood test:

Lab chain	Typical price band	Notes
Dr Lal PathLabs	Typically &rupee;800–&rupee;1,400	Wide network; online booking often slightly cheaper
Metropolis Healthcare	Typically &rupee;700–&rupee;1,300	Frequent online discounts
Thyrocare (via partner labs)	Typically &rupee;700–&rupee;1,200	Often the lowest list price; home collection available
Apollo 24\|7	Typically &rupee;750–&rupee;1,300	Integrated with Apollo hospitals
Orange Health	Typically &rupee;800–&rupee;1,400	Home-collection focused in metro cities

These are approximate bands, not quotes: prices change often and vary by city, and home collection can add a small fee. Where possible, choose a NABL-accredited lab, and remember the reference range printed on your own report is the one that counts.

Frequently Asked Questions

What time of day should cortisol be tested?

Morning — usually between 7 and 9 am — for a baseline, because cortisol peaks early. But the right timing depends on what your doctor is investigating, so follow the prescription exactly.

Do I need to fast or rest before a cortisol test?

Usually a rested morning sample: avoid strenuous exercise and major stress beforehand, and skip the test during acute illness if it is meant as a baseline. Ask the lab for their specific protocol.

Can my steroid inhaler affect the cortisol result?

Yes. Steroids in any form — tablets, inhalers, creams, nasal sprays, injections — can suppress your own cortisol. List every one of them; never stop a prescribed steroid for a test without your doctor's instruction.

My cortisol is slightly high — do I have Cushing's syndrome?

A single mildly high value does not diagnose Cushing's — stress, poor sleep, and timing commonly explain it. Doctors confirm with specific timed tests, so discuss the result rather than worrying over one number.

How much does the Cortisol test cost in India?

The Cortisol test typically costs ₹700–₹1,400 in India, though prices vary by city and lab. Choose a NABL-accredited lab where possible — and remember the reference range printed on your own report is the one that counts. Discuss the result with your doctor.

Pharmacist's practical notes

The medicine list is the hidden variable in cortisol testing: steroid inhalers, skin creams, joint injections and nasal sprays all reach the bloodstream in small amounts, and all can suppress the adrenal axis or distort results. People routinely forget the cream and remember the tablet — bring everything, including over-the-counter steroids.

Never stop a steroid medicine because of a cortisol result without medical supervision: long-term steroids suppress the body's own cortisol production, and abrupt stopping can be dangerous. Any taper is a doctor-supervised process, not a lab-driven decision.

In India

Indian labs usually report cortisol in µg/dL. The blood test typically costs &rupee;700–&rupee;1,400, though prices vary by city and lab; confirmatory dynamic tests are priced separately.

Where possible, choose a NABL-accredited lab. Insist on the exact draw time being recorded — an untimed cortisol is barely interpretable.

References

Sources cited on this page. PubMed links open the original abstract.

Bornstein SR, Allolio B, Arlt W, et al. Diagnosis and treatment of primary adrenal insufficiency: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2016;101(2):364–389. PMID 26760044 · doi:10.1210/jc.2015-1710
Kim YJ, Ahn CH, Cho YY, et al. Stimulated Salivary Cortisol as a Noninvasive Diagnostic Tool for Adrenal Insufficiency. Endocrinol Metab (Seoul). 2020;35(3):628–637. PMID 32981305 · doi:10.3803/EnM.2020.707
Nieman LK, Biller BMK, Findling JW, et al. The Diagnosis of Cushing's Syndrome: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2008;93(5):1526–1540. PMID 18334580 · doi:10.1210/jc.2008-0125

Why timing matters, the cortisol diurnal rhythm

Cortisol is not produced at a constant rate, it follows a circadian rhythm that is essential to understand before interpreting any result. Cortisol peaks between 6 and 9 am (reaching 400–700 nmol/L), falls gradually throughout the day, and reaches its nadir at midnight (typically below 50 nmol/L). A 9 am cortisol reflects peak physiological output; a random cortisol taken at any other time is largely uninterpretable without knowing the exact time of collection.

Reference ranges on laboratory reports are typically given for early morning samples. A "normal" 9 am cortisol does not indicate normal cortisol function throughout the day, for suspected Cushing's syndrome, late-night cortisol (which should be suppressed) is more diagnostically sensitive than a morning cortisol (which may be normal in Cushing's due to preserved, though dysregulated, morning rhythm).

Tests for cortisol deficiency (adrenal insufficiency)

9 am serum cortisol: Above 450–500 nmol/L is virtually normal (adrenal insufficiency unlikely). Below 100 nmol/L is virtually diagnostic of adrenal insufficiency. Between 100 and 450 nmol/L is a "grey zone" requiring dynamic testing.
Short synacthen test (SST): The gold standard for diagnosing primary adrenal insufficiency. Synthetic ACTH (250 µg IV or IM) is given at time zero; cortisol is measured at 30 and 60 minutes. A peak cortisol above 420–500 nmol/L (laboratory-dependent) is a normal response, adrenal insufficiency is excluded. A subnormal peak confirms adrenal insufficiency. The SST does not reliably detect secondary adrenal insufficiency (pituitary problem) in the first weeks after pituitary damage, the adrenals are not yet atrophied and may respond normally. Insulin tolerance test (ITT) is used in this context but is only performed in specialist centres due to hypoglycaemia risk. Salivary cortisol sampling is increasingly used as a non-invasive alternative to venous sampling in this work-up.²
ACTH: A simultaneous ACTH measurement localises the cause. High ACTH + low cortisol = primary adrenal insufficiency (Addison's disease, adrenal glands failing). Low ACTH + low cortisol = secondary adrenal insufficiency (pituitary or hypothalamic cause, or long-term steroid suppression).

Tests for cortisol excess (Cushing's syndrome)

Endocrine Society guidance recommends starting with one of three tests of similarly high accuracy, 24-hour urinary free cortisol, late-night salivary cortisol, or a 1 mg overnight (or 2 mg 48-hour) dexamethasone suppression test, and confirming an abnormal result with a second, different test before proceeding to find the cause; a single normal result does not usually need further work-up.³

Late-night salivary cortisol: The most sensitive and convenient screening test. A midnight salivary cortisol above 9.0 nmol/L (laboratory-specific) on two occasions is strongly suggestive of Cushing's syndrome. Salivary collection is non-invasive and can be done at home.
24-hour urinary free cortisol (UFC): Measures integrated daily cortisol production. Above the upper limit of normal on two collections suggests Cushing's. False positives occur in stress, exercise excess, depression, and pseudo-Cushing's (alcohol-related).
Overnight 1 mg dexamethasone suppression test (DST): The pituitary should suppress ACTH (and hence cortisol) when dexamethasone is given. A cortisol above 50 nmol/L the following morning indicates failure to suppress, seen in Cushing's syndrome and pseudo-Cushing's states. Sensitivity approximately 90%; needs confirmatory testing.

Medical Disclaimer: This page is for general educational purposes only and does not constitute medical advice. Always consult a qualified doctor for diagnosis and treatment decisions.