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Cortisol guide

What causes high cortisol, and which causes are medical.

Most articles on this question answer "stress" and stop. Stress is on the list. It is not at the top of it, it is not the cause that hurts people, and the cause that does is a medicine that several million of us take. Here is the full list, in the order that matters, with the sources.

The short answer

Cortisol rises for everyday reasons and for medical ones, and the two are not the same size. Stress, short sleep, alcohol, caffeine and night shifts move cortisol on a timescale of hours. Sustained, pathological excess almost always has a medical cause, and the most common one by a wide margin is corticosteroid medication such as prednisone. The rest are Cushing's syndrome, chronic heavy drinking, major depression, poorly controlled diabetes and sleep apnea. Never stop or reduce a steroid on your own.

Read this first if you take steroid medication

The most common cause of pathological cortisol excess is a prescription, which means the single most dangerous thing an article like this can do is send you to your medicine cabinet. So, before anything else.

Never stop or reduce a steroid on your own. The FDA label for prednisone says it plainly: patients should be warned not to discontinue corticosteroids abruptly or without medical supervision. Abrupt withdrawal can precipitate an adrenal crisis, which is life-threatening. If your steroid dose is the problem, changing it is your prescriber's job, on a plan, with a taper.

If you take steroids by any route, this page is about you. Not just tablets. NICE defines the at-risk group as people taking or recently stopped from glucocorticoids by any route of administration for more than 4 weeks (more than 3 weeks if under 16). In the pooled data from Broersen and colleagues, measured adrenal insufficiency ran from 4.2% for nasal steroids to 52.2% for joint injections, which was the highest of any route, above oral. Inhalers, creams, nose sprays and injections all count.

An adrenal crisis looks like a stomach bug. Vomiting, diarrhoea, abdominal pain, severe weakness, confusion, low blood pressure, collapse. A gastrointestinal illness is also one of its common triggers, which is what makes the misread so easy.

  • If you vomit a dose, you have not taken it, and you must replace it. This is the mechanism that kills people. NICE gives two steps and you need both. Step one: if you vomit within 30 minutes of an oral dose, take another dose as soon as the vomiting settles, at double the original dose. Step two: if vomiting recurs within 30 minutes of that, or you cannot keep anything down, give intramuscular hydrocortisone and go to the emergency department. If you have an emergency injection kit, this is what it is for. Prolonged diarrhoea stops you absorbing tablets too, and is treated the same way: if it will not settle, use the injection and get seen.
  • Call an ambulance and say the words. "I take steroid medication, I cannot keep it down, this may be an adrenal crisis." Ask for hydrocortisone. NICE advises going to hospital by ambulance without waiting for a referral. Carry a steroid emergency card or medical ID; ask your prescriber or pharmacist for one.
  • No fever does not mean you are safe. Fever is a useful sign when it is there and a useless one when it is not: the prednisone label states that corticosteroids mask some signs of infection. The absence of a fever rules out neither an infection nor a crisis.
  • When you are ill or having surgery you may need more steroid, not less. The label: "Increased dosage of rapidly acting corticosteroids is indicated in patients on corticosteroid therapy subjected to any unusual stress before, during and after the stressful situation." Ask your prescriber for your sick-day rules before you need them, and write them down. For fever or infection NICE's floor is at least 40 mg of oral hydrocortisone daily in 2 to 4 divided doses (or the equivalent of your own steroid) until the illness resolves.

If you are coming off a course, what actually happens to your body during a steroid taper covers the recovery period in detail.

The other thing to check first: this symptom set is not specific

People arrive at this search with a cluster: tired but wired, weight settling around the middle, broken sleep, anxiety, new high blood pressure. Cortisol is one explanation for that cluster. It is not the only one, and some of the others are both more common and more treatable. Two of them raise cortisol themselves, which is exactly why they get mistaken for it.

  • Obstructive sleep apnea. It appears on the endocrinology list of non-neoplastic causes of hypercortisolism, so it can both mimic and produce raised cortisol. The signs that separate it: heavy snoring, witnessed pauses in breathing or gasping in your sleep, falling asleep during the day. It is diagnosed with a sleep study and it is treatable.
  • Thyroid disease, and it runs in both directions. An underactive thyroid gives fatigue, weight gain, feeling cold, dry skin, hair thinning. An overactive one gives the "tired but wired" picture that probably brought you to this page: anxiety, broken sleep, fatigue, muscle weakness, raised blood pressure. The signs that separate the overactive kind: heat intolerance and sweating, tremor in the hands, weight loss despite eating normally, and a fast or irregular heartbeat. That last one matters, because untreated it can cause atrial fibrillation and stroke, and a thyroid storm is a medical emergency. Get a fast or irregular heartbeat looked at promptly rather than filed under anxiety. One blood test settles either direction.
  • Undiagnosed or poorly controlled diabetes. The Endocrine Society guideline names poorly controlled diabetes among the conditions that raise cortisol without Cushing's syndrome. The signs that separate it: thirst, passing a lot of urine, unexplained weight loss, blurred vision.
  • Major depression, which also raises cortisol. If you are having thoughts of harming yourself, that is not a data problem and it is not a hormone problem to solve at home. In Canada and the United States, call or text 9-8-8.

Those separating signs are useful when they are there and close to useless when they are not. Plenty of people with sleep apnea do not snore, and plenty sleep alone, so nobody has ever witnessed a pause. Type 2 diabetes is very often completely silent until a blood test finds it. A sign you do not have is not a test you have passed. None of these is diagnosed from a symptom list, a search engine, an app, or a wearable, including ours. They are diagnosed by a clinician with proper testing, and each one on that list has a treatment worth having.

What actually raises cortisol?

Cortisol has two kinds of cause, and conflating them is the single biggest error in the popular coverage of this topic. One kind moves your cortisol by the hour and by the day. The other kind produces sustained excess that changes a body over months. A bad week at work belongs firmly in the first column, and it is worth being precise about that rather than flattering the anxiety that brought you here.

Cause What it does to cortisol Evidence
Acute stressRaises it within minutes, then it comes back downThis is the system working, not failing
Chronic stressChanges the shape of the daily rhythm more reliably than it changes the totalSee cortisol and stress
Short or broken sleepRaises the next evening's cortisol and delays its fallEvening cortisol 37% higher after a 4-hour night, 45% after none (Leproult 1997)
Night-shift workMis-times the rhythm rather than simply raising itBlunted waking rise after night shifts (Sci Rep 2022). IARC classes night-shift work Group 2A
CaffeineRaises it across the day, with partial tolerance in daily drinkers250 mg three times in a day raised cortisol in 96 adults (Lovallo 2005)
AlcoholRaises it acutely. Heavy chronic use can produce full hypercortisolism8 cases indistinguishable from Cushing's syndrome (Front Endocrinol 2023)
Corticosteroid medicationThe most common cause of pathological cortisol excessNIDDK: the most common cause of Cushing's syndrome
Cushing's syndrome (from a tumour)Sustained excess. RareNIDDK: about 40 to 70 people per million
Depression, alcohol use disorder, diabetes, sleep apnea, kidney diseaseGenuine hypercortisolism, sometimes with a cushingoid appearanceNon-neoplastic hypercortisolism (J Endocr Soc 2023)

What are the medical causes of high cortisol?

This is the section most articles replace with the phrase "an underlying issue." The underlying issues have names, and the names are useful.

1. Corticosteroid medication, and it is not close

The NIDDK states that the most common cause of Cushing's syndrome is the long-term, high-dose use of the cortisol-like glucocorticoids. Prednisone, prednisolone, dexamethasone, hydrocortisone, budesonide, and the rest. They are prescribed for asthma, rheumatoid arthritis, lupus, inflammatory bowel disease, transplants, and a long list of other conditions where they do a great deal of good.

Two things follow, and they point in opposite directions, which is why the topic gets handled badly.

2. Cushing's syndrome from a tumour, which is rare

When the body itself overproduces cortisol, it is usually a small pituitary tumour driving the adrenal glands. The NIDDK puts pituitary tumours behind 8 out of 10 cases of the tumour-driven form, and the whole endogenous group at roughly 40 to 70 people per million. The other 2 in 10 matter more than their share suggests: a tumour on the adrenal gland itself, which the NIDDK notes is usually benign but sometimes cancerous, or an ACTH-producing tumour somewhere else, most often in the lung. Rare is not zero, and the NIDDK is blunt about the stakes: Cushing's syndrome can usually be cured, but it can be fatal if it is not treated.

The fast version is the dangerous one, and it does not look like the slow one. When the cortisol excess comes from a lung tumour or an adrenal cancer it can build over weeks, and the picture inverts: weight loss instead of central weight gain, deep weakness in the arms and legs, darkening of the skin, severe new high blood pressure, swelling, and a low potassium on bloods. If your symptoms have appeared and worsened over a few weeks, do not measure yourself against the slow, thickening picture in the paragraph above. Get seen now.

The Endocrine Society's clinical practice guideline is direct about how this is approached, and both halves are worth reading. First, iatrogenic Cushing's syndrome arising from exogenous corticosteroids (oral, rectal, inhaled, topical or injections) must be excluded prior to testing. Second, "endogenous CS is uncommon, hence widespread testing is not encouraged." The guideline names four features as the most discriminating:

These are useful as positives and close to useless as negatives. Not having them does not rule cortisol excess out, and it certainly does not rule out the far more common causes in the row above and the rows below. A sign you do not have is not a test you have passed. What the guideline is telling a clinician is who to test, not who is well.

3. Non-neoplastic hypercortisolism: the causes nobody names

Endocrinology recognizes a group of conditions that produce genuinely raised cortisol, sometimes with the full cushingoid appearance, in the absence of any tumour. The current review in the Journal of the Endocrine Society lists, among those that produce a Cushing phenotype: alcohol use disorder, major depression and other neuropsychiatric conditions, poorly controlled type 2 diabetes, obstructive sleep apnea, chronic kidney disease at stages 4 to 5, and pregnancy.

The alcohol version deserves its own paragraph, because it is the one people rule out for themselves by mistake. A 2023 case series in Frontiers in Endocrinology reported 8 patients drinking 3 to 12 drinks daily over 4 to 20 or more years. Seven of the eight had overt physical findings, among them facial rounding and plethora, truncal weight, a dorsocervical fat pad and violaceous striae. All 8 had abnormal dexamethasone suppression testing and raised late-night salivary cortisol, which is to say they looked biochemically like Cushing's syndrome. One had an adrenal gland removed, with no reduction in hypercortisolism at all. Of the eight, three stopped drinking and their cortisol excess normalised; the literature the authors review puts resolution at roughly 1 to 2 months after abstinence. One patient initially denied drinking entirely.

If you are a heavy daily drinker, do not simply stop

The obvious action item from the paragraph above is the one that can hurt you. Sudden cessation of alcohol after regular heavy drinking can cause withdrawal, and severe withdrawal (seizures and delirium tremens) can be fatal. MedlinePlus is unambiguous: alcohol withdrawal is a serious condition that may quickly become life-threatening.

The action is to tell a doctor how much you actually drink and stop with medical help, not to white-knuckle it starting tonight. Seek emergency care for seizures, fever, severe confusion, hallucinations or an irregular heartbeat during withdrawal.

This is a doctor's job, not a wearable's

Cushing's syndrome, adrenal insufficiency, thyroid disease, sleep apnea and diabetes are all diagnosed by clinicians using proper testing. None of them is diagnosed from a symptom list, a mirror, an app, or a wearable, including ours. Nothing on this page is a diagnosis, and the Auromone Curve cannot give you one.

Book an appointment if your symptoms have progressed over weeks or months, if you have any of the four discriminating features above, if you take steroid medication by any route, or if you drink heavily. Book one too if your symptoms are unusual for your age, which is a trigger the Endocrine Society names directly, giving early osteoporosis and new high blood pressure in a young person as its examples. Book one if a scan has ever found an unexplained lump on an adrenal gland. And note that symptoms which began during a stressful stretch are not thereby explained by it. Stress is a common coincidence, not an alibi. Bring the specifics: what changed, when, and how fast.

Does stress cause high cortisol?

Yes, acutely, and that is not a malfunction. Cortisol rises within minutes of a threat, real or imagined, mobilises glucose, and comes back down. A system that did not do this would be a broken one. Nobody needs a wearable to know they had a bad Tuesday.

The claim that does not hold up is the bigger one: that ordinary psychological stress produces the sustained, pathological excess that reshapes a body. It does not appear to. That is what makes the popular framing of "cortisol face" and cortisol belly wrong, and it is why the medical causes above exist as a separate category rather than as the far end of the same spectrum.

Read that as a claim about a mechanism, not as a verdict about you. If you feel wrong and you have felt wrong for months, the fact that a stressful job does not cause Cushing's syndrome is not reassurance. It is a reason to look somewhere better than the stress narrative, which is where the box at the top of this page and the signs people associate with high cortisol come in.

What chronic stress does do, reliably, is change the shape of the curve: when cortisol peaks, how steeply it falls, and whether it is still up at midnight when it should be at its floor. That is a timing story rather than a level story, which is exactly why clinicians assessing cortisol use timed tests such as late-night salivary cortisol, dexamethasone suppression and 24-hour urine, rather than one daytime blood draw.

Does lack of sleep raise cortisol?

Yes, and the bill arrives the following evening. This is one of the cleanest findings in the literature and it is almost always reported vaguely, so here are the actual numbers.

Leproult, Copinschi, Buxton and Van Cauter (Sleep, 1997) measured plasma cortisol across 32 hours in healthy young men. After a night in bed only from 4am to 8am, evening cortisol (the 6pm to 11pm window) was 37% higher the next day. After a night of no sleep at all, it was 45% higher. In both cases the onset of the quiet, low-cortisol period was delayed by at least 1 hour.

The delay matters as much as the height. Cortisol is supposed to be near its floor in the evening, which is roughly the condition for falling asleep. Push it up and hold it up, and the next night is worse, which pushes the following evening up again. Cortisol and sleep follows that loop in detail.

One honest caveat: those were young, healthy men in a lab, deprived for one night. It is a mechanism study, not a description of your life. It is still the best-quantified answer available to the question you asked.

Do caffeine and alcohol raise cortisol?

Both do, and the difference between them is that one of the two has a pathological version.

Caffeine. Lovallo and colleagues gave 96 healthy adults caffeine as 250 mg at 9am, 1pm and 6pm (roughly 2 to 3 cups per dose, not per day) and measured a significant rise in cortisol across the test day. In people who consumed caffeine daily, the response was reduced but not eliminated: tolerance was incomplete at 300 mg a day and more complete at 600 mg a day. So the honest version is that your coffee raises your cortisol, that it raises it less if you drink coffee every day, and that nobody has shown this to be the thing wrecking your health. We are not going to inflate it into one. You will see a figure of "50%" attached to this study in a lot of articles. It is not in the paper.

Alcohol. Different story, as the case series above makes clear. Acute drinking raises cortisol, and sustained heavy drinking can produce hypercortisolism that is biochemically and clinically indistinguishable from Cushing's syndrome, up to and including an unnecessary adrenalectomy. It is under-recognised, and it is reversible: in the patients who did stop, the cortisol excess normalised. That is a genuinely good piece of news attached to a genuinely hard action. Read the callout above before you act on it.

Does shift work raise cortisol?

Not exactly. It moves it, which is arguably worse, and it is the reason shift workers are so poorly served by articles about "lowering" cortisol. If you work nights, most of the advice on this topic quietly assumes you sleep at night, and you will have noticed that it does not fit.

In a 2022 study of female hospital employees in Scientific Reports (66 shift workers, 21 non-shift workers), the cortisol awakening response after night shifts, when the women were waking from daytime sleep, was lower than before day shifts, not higher. The authors attributed it to a mismatch between the time of waking and the body's own cortisol peak, which stays anchored to the clock rather than to your alarm. The problem is misalignment, not magnitude.

This is not a small effect on a small group. In 2019 the International Agency for Research on Cancer classified night-shift work as Group 2A, probably carcinogenic to humans, on the basis of circadian disruption, with positive associations observed for cancers of the breast, prostate, colon and rectum. That is not a cortisol claim and it should not be reported as one. It is the reason circadian misalignment is treated as a serious exposure rather than an inconvenience.

Which of these can you actually see?

Look back at the list. The medical causes are a clinician's work and this page has told you where to take them. The everyday causes are a different kind of question, and they share an awkward property: they all act on cortisol over hours, and none of them announce themselves. You do not feel a 37% higher evening. You infer it, badly, from how you slept.

Cortisol itself can be measured. The Auromone Curve is designed to read cortisol from a trace of sweat on your wrist, continuously, so that the shape of your own day is something you look at instead of guessing at. It ships Q4 2026.

To be exact about what that is not: it is not a test, it cannot detect or rule out any condition on this page, and it will not tell you why you feel the way you do. Clinicians assess cortisol excess with specific tests, and a general wellness reading is not one of them and cannot be compared to one. If you want the ranges and what they mean, normal cortisol levels covers the clinical numbers, and Cortisol 101 is the place to start on the hormone itself. If you came here looking for what to do next, how to lower cortisol is the companion piece to this one.

This guide is for general wellness education only. The Auromone Curve is a general wellness device, not a diagnostic, and does not replace medical advice or clinical testing. Never start, stop or change a prescribed medication on the basis of anything you read here. Please talk to a healthcare provider.

References

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Straight answers

What causes high cortisol: FAQ

What causes high cortisol?

Cortisol rises for everyday reasons and for medical ones, and the two are not the same size. The everyday causes are stress, short or broken sleep, alcohol, caffeine, and night-shift work, and they move cortisol on a timescale of hours. Sustained, pathological cortisol excess is a different thing, and it almost always has a medical cause. Corticosteroid medication such as prednisone is the most common of those, according to the National Institute of Diabetes and Digestive and Kidney Diseases. Cushing's syndrome, chronic heavy alcohol use, major depression, poorly controlled diabetes, and obstructive sleep apnea are the others endocrinology names most often.

What is the most common cause of high cortisol?

Corticosteroid medication. The NIDDK states that the most common cause of Cushing's syndrome is the long-term, high-dose use of the cortisol-like glucocorticoids, and that includes prednisone tablets as well as inhaled, topical, nasal, injected and joint-injected steroids. If you take steroids by any route, do not stop or reduce the dose on your own. Stopping abruptly can cause an adrenal crisis, which is life-threatening. Take it to the doctor who prescribed it.

Can stress alone cause high cortisol?

Stress raises cortisol acutely, within minutes, and that is the system working as designed. What ordinary psychological stress does not appear to do is produce the sustained, pathological excess that reshapes a body. That is a statement about a mechanism, not a verdict on how you feel. If your symptoms are real and have persisted for weeks or months, the fact that stress does not cause Cushing's syndrome is a reason to keep looking, not a reason to stop.

Does lack of sleep raise cortisol?

Yes, and the effect lands the following evening rather than the same night. In a study by Leproult and colleagues published in Sleep in 1997, young men who were in bed only from 4am to 8am had evening cortisol 37% higher the next day, and men kept awake all night had it 45% higher, with the normal evening fall delayed by at least an hour. Sleep loss does not only raise cortisol. It changes when cortisol comes down.

When should I see a doctor about high cortisol?

See a doctor if you take steroid medication by any route, if your symptoms have progressed over weeks or months, if your symptoms are unusual for your age, or if you have the features the Endocrine Society guideline calls the most discriminating for Cushing's syndrome: easy bruising, a flushed round face, weakness in the muscles closest to the trunk such as difficulty rising from a chair, and reddish-purple stretch marks. The absence of those features does not rule cortisol excess out, and symptoms that began during a stressful stretch are not thereby explained by it. If you take steroids and vomit a dose within 30 minutes of taking it, NICE advises taking a further dose at double the original once the vomiting settles, and if vomiting recurs within 30 minutes, giving intramuscular hydrocortisone and attending the emergency department. Go the same day, or call emergency services, if you take steroids and cannot keep them down, or if you have vomiting, diarrhoea, severe weakness, confusion or collapse.

Take the medical half of this page to a doctor.

That is the actual call to action on this page, and it is not ours to profit from. Sleep, alcohol, caffeine and a night shift all moved your cortisol, and none of them are why you would be reading this at 2am. If you take steroids and cannot keep them down, or you have vomiting, diarrhoea, severe weakness, confusion or collapse, that is the same day or emergency services, not a measurement. If you want to understand the hormone itself afterwards, Cortisol 101 is here and it will keep.