What high cortisol does to your body: short-term and long-term effects

What high cortisol does to your body depends on how high, for how long, and why. A short rise is part of normal life. Years of very high cortisol, as in Cushing’s syndrome, are linked with serious problems.

The mistake to avoid is treating the two as the same thing. This page separates them and says where the evidence is thin.

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What cortisol normally does

MedlinePlus says cortisol affects almost every organ and tissue. It helps your body respond to stress, reduce inflammation, control blood glucose and metabolism, and control blood pressure. NIDDK adds that it helps turn the food you eat into energy.

So the question isn’t whether cortisol is good or bad. You need it. The question is when it is too much. See is cortisol good or bad.

Short-term effects of a cortisol rise

When you face a challenge, MedlinePlus says the stress hormones that are released make you alert and ready to act, and can raise blood pressure, heart rate and blood glucose. It also says that not all stress is bad, and that a little short-term stress can sometimes be helpful.

A review of how glucocorticoids affect insulin describes it the same way: acute release mobilizes energy for fight or flight. These effects end when the stressor does. See cortisol spikes.

What long-term excess is linked with

NIDDK lists the health problems Cushing’s syndrome can cause:

• Heart and circulation. Heart attack and stroke, blood clots in the legs and lungs, high blood pressure and unhealthy cholesterol levels.
• Blood sugar. Insulin resistance, prediabetes and type 2 diabetes.
• Bones. Bone loss and fractures.
• Infections. Cushing’s syndrome can make infections more likely.
• Mood and thinking. Depression or other mood changes, memory loss and trouble concentrating.

NIDDK also lists the physical signs, such as easy bruising, wide purple stretch marks, thin arms and legs and weak muscles. For women it lists irregular or stopped periods. For men it lists lower fertility, a lower interest in sex and erectile dysfunction. See high cortisol symptoms, high cortisol in women and high cortisol in men.

NIDDK says Cushing’s syndrome can be fatal if not treated. These effects describe people with very high cortisol for a long time. They don’t describe a busy week.

High cortisol and blood sugar

This is the link the sources describe most clearly. MedlinePlus says cortisol helps control blood glucose. NIDDK says Cushing’s syndrome can lead to insulin resistance, prediabetes and type 2 diabetes, and may be the cause in some people who have type 2 diabetes with blood glucose that stays too high, along with high blood pressure. A review in the International Journal of Molecular Sciences says long-term glucocorticoid exposure, from drug treatment or Cushing’s syndrome, progressively leads to insulin resistance.

The evidence is about glucocorticoid excess. It isn’t about the ups and downs of normal cortisol. A 2020 genetic study in BMC Medicine used genetic variants that predict cortisol levels. It found no association between genetically predicted cortisol and heart disease, stroke, type 2 diabetes or their risk factors. The authors say their results find no evidence that cortisol plays a role in cardiovascular risk, though they say replication is warranted. So observational links between cortisol and these conditions may not mean cortisol is the cause. See cortisol and blood sugar.

High cortisol, mood and thinking

NIDDK lists depression or other mood changes, and memory loss or trouble concentrating, among the complications of Cushing’s syndrome. A primary care review says depression and other mood disorders occur alongside hypercortisolism in as many as 60 percent of cases in some reports, that the link may run both ways, and that treating the cause of the high cortisol doesn’t always resolve them completely.

For everyday anxiety and mood, the picture is looser. A 2020 review in Frontiers in Psychiatry says overactivity of the stress-hormone system has been seen in certain subgroups of people with anxiety and mood disorders, not in all. See cortisol and anxiety.

High cortisol and sleep

Sleep and cortisol affect each other. In the Whitehall II study of more than 3,000 adults, recurrent short sleep was associated with a flatter daily cortisol pattern and higher cortisol later in the day. The authors call these associations. They don’t show that one causes the other. See cortisol and sleep.

Is high cortisol bad?

For one result or one stressful day, no, not by itself. The body needs cortisol to rise and fall.

The harm in the sources comes from sustained excess. Short rises that fade are the normal pattern, and the long-term harms NIDDK describes come from cortisol that stays high for a long time. The sources we checked don’t support many of the broader claims made about “too much cortisol” in ordinary life, so be careful with any page that lists dozens of effects.

If you are worried about your own situation, the useful step is a conversation with a clinician about your symptoms, your medicines and what test, if any, fits.

What this page doesn’t cover

This page describes effects. It doesn’t cover treatment. If you take a steroid medicine, don’t stop it or change the dose because of anything here. Ask the prescriber. If you think you may have Cushing’s syndrome, see a clinician. A single blood cortisol can’t diagnose or rule it out, so testing for high cortisol explains which tests clinicians use.

Questions people ask

What does high cortisol do?

In the short term it helps you respond to stress, and it raises blood pressure, heart rate and blood glucose to do it. In the long term, excess is linked with a list of problems, including high blood pressure, diabetes, bone loss, infections and mood changes.

What does too much cortisol cause?

NIDDK links Cushing’s syndrome, meaning too much cortisol over a long time, with heart attack, stroke, blood clots, infections, bone loss, high blood pressure, unhealthy cholesterol, mood changes, memory problems, insulin resistance and type 2 diabetes.

What does high cortisol mean?

A cortisol measurement above a range for that sample, time of day and lab. It doesn’t say why. See what a high cortisol level means.

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.

• Causes of high cortisol

  Medicines, conditions and normal ups and downs.

• Is cortisol good or bad?

  Why the body needs it.

• Cortisol and blood sugar

  What is known about cortisol and glucose.