What causes high cortisol? Medicines, conditions and normal swings

What causes high cortisol depends on what “high” means. A high lab result has many causes, most of them ordinary. Long-term cortisol excess, called Cushing’s syndrome, has a short list of causes, and the most common one is a medicine.

This page sorts the causes by how often they come up and how much they matter, so you can see where your own situation might fit.

Cortisol

One blood draw for one cortisol result. It can’t diagnose or rule out an adrenal condition by itself.

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A single blood cortisol can't diagnose or rule out Cushing's syndrome, and many ordinary things raise it. If you take a steroid medicine, ask your prescriber how it affects results, and never stop it for a test.

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The causes at a glance

Group	Examples	What the sources say
Normal body responses	Stress, exercise, hot or cold temperatures, time of day, pregnancy	MedlinePlus lists stress, pregnancy, exercise and temperature as things that affect results, and says levels vary during the day.
Medicines	Prednisone and similar glucocorticoids, injections, creams, oral estrogen	The most common cause of abnormal cortisol is taking steroid medicines for a long time or stopping them suddenly.
Other conditions	Depression, anxiety, alcohol use disorder, poorly controlled diabetes, obesity	Called pseudo-Cushing syndrome. Cortisol can run high, and may come and go.
Tumors	Pituitary, adrenal, or elsewhere in the body	Rare. NIDDK puts endogenous Cushing’s at about 40 to 70 per million people.
The test itself	Timing, carrier proteins, lab method	Can read high without cortisol being high in the body.

Normal reasons cortisol goes up

Cortisol is a stress hormone, and MedlinePlus says it helps your body respond to stress. Stress and exercise can raise it, as can hot and cold temperatures and pregnancy.

Time of day. Cortisol follows a daily rhythm. The Endocrine Reviews paper says it rises from about 4 a.m. in people who sleep at night and peaks within three hours of waking. A high value in the morning is expected. See high cortisol in the morning.

Short stress. A review in Frontiers in Endocrinology defines an acute stressor, such as a near-miss in traffic, as one that triggers an immediate response that usually subsides shortly after the stressor ends. MedlinePlus adds that stress hormones raise blood pressure, heart rate and blood glucose, and that not all stress is bad. See cortisol spikes.

Long stress. Chronic stress, such as work, money or family pressure that doesn’t stop, can harm health, according to MedlinePlus. The same Frontiers review says the stress literature has heterogeneous findings about its effects on the brain and body. So the common claim that chronic stress keeps cortisol high is not something the sources we checked settle.

Sleep and shift changes. Acute changes in the sleep-wake cycle, such as shift work or jet lag, activate the stress-hormone system and change the normal pattern, according to Endocrine Reviews. In the Whitehall II study of more than 3,000 adults, recurrent short sleep was associated with a flatter daily pattern and higher cortisol later in the day. That is an association. See cortisol and sleep.

Medicines that raise cortisol or a cortisol result

Glucocorticoids. NIDDK says the most common cause of Cushing’s syndrome is long-term, high-dose use of cortisol-like glucocorticoids. They treat conditions such as asthma, rheumatoid arthritis and lupus, and they are used after organ transplants. They are also injected into joints for pain. MedlinePlus counts pills, shots, inhalers and creams when it asks about steroid use. NIDDK says more than 10 million Americans take glucocorticoids each year, and it isn’t known how many of them develop Cushing’s syndrome. See prednisone and cortisol.

Hidden steroids. A laboratory review says potent glucocorticoids can be present in cosmetics and herbal creams, and that exposure can be unintentional.

Oral estrogen. This doesn’t raise cortisol in the body. It raises the carrier protein that holds most of it, so a total blood cortisol reads high. MedlinePlus lists birth control pills as something that can affect results. See birth control and cortisol.

Stopping steroids. MedlinePlus says stopping a steroid medicine suddenly can lower cortisol. Don’t stop or change a steroid on your own. Ask the prescriber.

Conditions that raise cortisol without Cushing’s syndrome

NIDDK says some people have high cortisol off and on without the long-term health effects of Cushing’s. MedlinePlus names the usual causes: depression, anxiety, alcohol use disorder, poorly controlled diabetes and obesity. A primary care review adds pregnancy, other psychiatric conditions, physical stress such as surgery or hospital stays, malnutrition and strenuous chronic exercise.

The signs can look like Cushing’s, and tests can read false positive. This is why doctors take a medical history before they test, and why they sometimes use a dexamethasone-CRH test to tell the two apart. See alcohol and cortisol.

Can high cortisol cause anxiety?

The relationship is not clear in either direction. A 2020 review in Frontiers in Psychiatry says overactivity of the stress-hormone system has been observed in certain subgroups of people with anxiety and mood disorders, not in all of them, and that some studies of generalized anxiety didn’t find it. NIDDK lists depression and other mood changes among the complications of Cushing’s syndrome. That is a statement about long-term excess, not about everyday cortisol swings. See cortisol and anxiety.

Tumors and Cushing’s syndrome

When Cushing’s is not caused by medicine, NIDDK names three sources:

• Pituitary tumors. These are noncancerous growths that make too much ACTH, which tells the adrenal glands to make cortisol. They cause 8 out of 10 cases that aren’t due to medicines, and doctors call this Cushing’s disease.
• Ectopic ACTH-producing tumors. Tumors outside the pituitary, most often in the lungs, can make ACTH too. They may be cancerous.
• Adrenal tumors. A tumor on the adrenal gland can make cortisol on its own. They are most often benign.

Once Cushing’s is diagnosed, NIDDK says the first step to find the source is measuring ACTH. Low ACTH points to an adrenal tumor. Normal or high ACTH points to a pituitary or ectopic tumor. That work belongs with an endocrinologist.

Causes that live in the test

Sometimes cortisol is not high in your body, but the number is.

• Carrier proteins. About 90 percent of blood cortisol is bound to a carrier protein. Anything that raises that protein, such as oral estrogen or pregnancy, raises total cortisol without raising the active, free portion.
• The lab method. Endocrine Reviews cites a study that compared five automated immunoassays with gas chromatography-mass spectrometry and reported a bias of 1.08 to 1.36 in the immunoassay results. Some immunoassays also cross-react with steroid medicines such as prednisolone.
• Timing and stress on the day. Stress and exercise can raise cortisol, and MedlinePlus says you may be asked to rest before a blood test.

Read more in what a high cortisol level means.

What to do with this

The order is the same whatever the cause. A clinician starts with your history and medicines. They may then order two of the standard Cushing’s tests: a 24-hour urine, a late-night saliva test, or a low-dose dexamethasone suppression test. A blood cortisol can give you a number to bring, but the cause is a clinical question. Testing for high cortisol covers the options.

Questions people ask

Why is my cortisol high?

If you have a result, the likeliest reasons are ordinary ones: the time of day, stress or exercise before the draw, a steroid medicine, or estrogen. If the result is high and you have specific signs such as easy bruising or muscle weakness, take it to a clinician. A single result can’t tell you which cause it is.

What causes cortisol to rise?

In healthy people, the body’s own rhythm raises it before and after waking, and stress and exercise raise it for a while. The causes of long-term rises are steroid medicines, some other conditions and, rarely, tumors.

Why is cortisol bad?

On its own it isn’t. MedlinePlus says cortisol helps with stress, inflammation, blood sugar and blood pressure. The trouble comes with too much for too long. See is cortisol good or bad and what high cortisol does to your body.

Keep reading

• High cortisol symptoms

  The signs doctors link to too much cortisol.

• What a high cortisol level means

  Ranges, timing and why a lab value isn't a diagnosis.

• Prednisone and cortisol

  How steroid medicines affect cortisol and results.

• Cortisol and alcohol

  What is known about alcohol and cortisol.

• Testing for high cortisol

  Which test answers which question.