Cortisol is a steroid hormone that regulates a wide range of body functions, including immunity, inflammation, and metabolism. Because of its role in regulating the stress response, people also call it the stress hormone.

Cortisol production and regulation involve a complex interaction between areas of the brain and the adrenal glands, which are located just above the kidneys.

Problems with any part of this system can lead to cortisol levels that are too high or too low, which can cause symptoms.

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Cortisol is a steroid hormone that affects almost every organ and tissue in the body. It helps regulate body functions such as:

  • stress response
  • inflammatory response
  • immunity
  • metabolism

Cortisol production and regulation involves a complex interaction between two areas of the brain called the hypothalamus and the pituitary gland, as well as two small glands called the adrenal glands, which sit just above the kidneys. Scientists refer to this system as the hypothalamus-pituitary-adrenal (HPA) axis.

The hypothalamus releases corticotropin-releasing hormone (CRH). This hormone instructs the pituitary gland to release adrenocorticotropic hormone (ACTH), which tells the adrenal glands how much cortisol to produce.

Once cortisol levels reach a certain level, they block the release of both CRH and ACTH. This type of self-regulating feedback loop is called homeostasis.

The HPA axis follows a circadian rhythm, in which cortisol levels are naturally high in the morning and low at night.

Cortisol works on special receptors called glucocorticoid receptors, which exist in almost allTrusted Source body tissues. For this reason, cortisol can affect almost every organ system in the body, including the following systems:

Cortisol regulates the following functions in the body:

  • immune and inflammatory responses
  • stress response
  • metabolism
  • blood sugar levels
  • blood pressure

Stress activatesTrusted Source a part of the nervous system called the sympathetic nervous system (SNS).

Once activated, the SNS triggers a hormonal and physiological reaction called the fight-or-flight response, which allows a person to fight or flee perceived danger by:

  • increasing heart and respiration rate
  • increasing blood flow to the muscles
  • increasing blood glucose concentration

A part of the brain called the amygdala processes the threat to determine whether the body needs to take further action.

If necessary, the amygdala sends a signal to the hypothalamus, which then activates the HPA axis. Once activated, the HPA axis releases a surge of cortisol. The extra cortisol provides an energy boost that allows a person to remain alert to potential danger.

Cortisol is one of several hormones that allow the body to react appropriately to perceived danger. However, chronic stress can lead to persistently high cortisol levels, which can be damaging to health.

Chronic high cortisol levels can cause a condition called Cushing syndrome. People with this condition may notice the following symptoms:

  • weight gain
  • muscle weakness
  • thin arms and legs
  • a rounded face
  • increased fat around the base of the neck
  • a fatty hump between the shoulders
  • easy bruising
  • wide purple stretch marks, which mainly appear on the following parts of the body:
    • abdomen
    • hips
    • breasts
    • underarms

Cushing syndrome is a rare condition, affecting around 10 to 15 people per million every year.

There are two main types: endogenous and exogenous. Endogenous Cushing syndrome develops because of an issue inside the body. Exogenous Cushing syndrome develops as a result of taking certain medications.

The most common cause of endogenous Cushing syndrome is a type of pituitary gland tumor called a pituitary adenoma. This type of tumor is typically slow-growing and benign.

The most commonTrusted Source cause of exogenous Cushing syndrome is the long-term use of high dose cortisol-like medications called glucocorticoids. This condition usually goes away once a person stops taking the medication.

Non-neoplastic hypercortisolism

Severe, persistent stress can resultTrusted Source in increased cortisol production, which can lead to pseudo-Cushing syndrome.

This can involve symptoms similar to those of Cushing syndrome. The symptoms tend to resolve once a person has addressed the cause.

Treatments for high cortisol

Treatments for high cortisol depend partly on the cause.

If a person is experiencing high levels of stress, they may find it helpful to speak with a healthcare professional. A healthcare professional may prescribe medications and provide information on how to manage stress.

Other possible treatment options include:

  • Adjustments to existing medications: If high cortisol levels are due to long-term glucocorticoid use, doctors will gradually taper the medication dosage to the lowest effective dose. Alternatively, a doctor may switch a person to a non-glucocorticoid medication.
  • Surgery: If high cortisol levels are due to a benign pituitary or adrenal tumor, surgery may be necessary to remove the tumor. Removal of a pituitary tumor is often highly successful, with a cure rate of up to 90%Trusted Source if an experienced surgeon performs the surgery.
  • Cancer treatments: In rare cases, high cortisol levels may be due to a cancerous tumor in some part of the HPA axis. Treatments will focus on destroying the cancer cells and may include some combination of surgery, radiation therapy, and chemotherapy.

Low cortisol levels can be a sign of adrenal insufficiency, a condition in which the HPA axis does not produce enough cortisol.

There are three typesTrusted Source of adrenal insufficiency:

  • Primary adrenal insufficiency: Also known as Addison’s disease, this type occurs when the adrenal glands do not produce enough cortisol and aldosterone. Aldosterone is a hormone that helps maintain the balance of sodium and potassium in the blood.
  • Secondary adrenal insufficiency: This type occurs when the pituitary gland does not release enough ACTH.
  • Tertiary adrenal insufficiency: This type occurs when the hypothalamus does not release enough CRH.

The most common symptoms of adrenal insufficiency include:

Treatments for low cortisol

The main treatmentTrusted Source for low cortisol levels, or adrenal insufficiency, is hormone medication to replace the hormones that the adrenal glands are no longer producing. The hormone medication doctors usually prescribe to replace cortisol is hydrocortisone. Less often, doctors may prescribe prednisone or dexamethasone.

People with Addison’s disease will also need to take a hormone medication called fludrocortisone to replace the aldosterone their adrenal glands are no longer producing. This medication helps balance sodium and fluid levels in the body.

Doctors can test cortisol levels by measuring the amount of cortisol in a person’s blood, urine, or saliva.

Blood test

When testing blood cortisol levels, a healthcare professional will usually take two blood samples in 1 day. They will take one in the morning, when cortisol levels are naturally at their highest, and another at around 4 p.m., when cortisol levels are naturally much lower.

Urine test

In some cases, doctors may suggest a 24-hour urinary free cortisol test. For this test, a person collects their urine over a 24-hour period. A doctor then sends the sample to a lab for further analysis.

A urine test that shows above-average cortisol levels may suggest Cushing syndrome, while a test that shows below-average cortisol levels may suggest adrenal insufficiency.

Saliva test

Another test that can help determine cortisol levels is a late night salivary cortisol (LNSC) test. For this test, a person collects a saliva sample in the late evening, when cortisol levels are naturally at their lowest.

An LNSC test that shows high cortisol levels may suggest Cushing syndrome.

A person should contact a doctor if they experience symptoms of high or low cortisol levels or if they have risk factors for Cushing syndrome or adrenal insufficiency.

The main risk factor for Cushing syndrome is long-term use of high dose glucocorticoid medications. Risk factors for adrenal insufficiency includeTrusted Source:

  • sudden discontinuation of corticosteroids after taking them for a long time
  • autoimmune diseases
  • removal of the adrenal glands or pituitary gland
  • genetic disorders that affect the development or function of the adrenal glands or pituitary gland
  • pituitary conditions, such as:
    • pituitary infections
    • pituitary tumors
    • a brain bleed that affects the pituitary gland

Cortisol is a steroid hormone that affects almost every organ and tissue in the body. It has a range of important functions, including regulating the body’s stress response, immune response, and inflammatory response and maintaining blood pressure and blood glucose levels.

Cortisol production and regulation involves a complex interaction between the brain’s hypothalamus and pituitary gland and the adrenal glands above the kidneys.

Problems in any part of this system can cause cortisol levels to become too high or too low. Problems can also result from taking cortisol-like medications for other health conditions.

High cortisol levels are a characteristic sign of Cushing syndrome, while low cortisol levels are a characteristic sign of adrenal insufficiency.

A person should consult a doctor if they experience symptoms of Cushing syndrome or adrenal insufficiency or if they have risk factors for either condition.