Effects of normal and abnormal levels of cortisol

Mike Bohl, MD, MPH, ALM - Contributor Avatar

Written by Chimene Richa, MD 

Mike Bohl, MD, MPH, ALM - Contributor Avatar

Written by Chimene Richa, MD 

last updated: Feb 20, 2020

4 min read

What is cortisol

Cortisol is a steroid hormone released by the adrenal glands, which are small glands that sit on top of your kidneys. You usually have some amount of cortisol in your body, and the levels fluctuate with early morning being the highest and decreasing during sleep (Lee, 2015).

However, when you are under stress, your brain secretes adrenocorticotropic hormone (ACTH) and triggers the release of extra cortisol from the adrenal gland as part of the "fight or flight" response—this is why cortisol is sometimes called the "stress hormone."

Cortisol has many actions in addition to the stress response, including raising blood glucose (sugar) levels, decreasing inflammation, and raising blood pressure. It also suppresses the digestive system and the reproductive system, to prepare to fight or flee.


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Stress response

When you are under stress, your body initially releases the "fight or flight" hormones, like epinephrine (also commonly called adrenaline), to raise your heart rate, dilate your pupils, increase your breathing, and more. However, this response is short-term, so your body also signals for cortisol release so that that body can stay in the "high alert" state until the stress has passed (Thau, 2017).

Blood glucose levels

As part of the role it plays in the stress response, cortisol also affects the glucose (sugar) levels in your blood. During times of stress, your body needs to use glucose as energy to fuel your "fight or flight" rather than storing it for future use.

Therefore, when cortisol levels are up, they trigger the breakdown of fat and muscle into the sugar molecules that the body can use for energy. It also stops the processes that your body uses to store glucose. In addition, cortisol tells the pancreas to decrease insulin production, which helps take up and store glucose, allowing more glucose to stay in the blood to be used.

Blood pressure

Cortisol increases your blood pressure by encouraging the kidneys to retain salt and water. This increases the overall volume of your blood, and more blood pumping through the vessels leads to higher blood pressure.


When cortisol levels go up due to stress, the body diverts its energies from fighting internal battles to address the external threat. In other words, since your body is revved up to give that presentation in front of hundreds of people, it is not going to devote as many resources to fighting off infections.

High levels of cortisol decrease both inflammation and your body's immune response by preventing the release of factors that trigger inflammation. Cortisol is part of a family of hormones called glucocorticoid hormones, and many of these are used as drug therapies to decrease immune responses. Hydrocortisone is the medication form of cortisol.

Abnormal cortisol levels

Having a normal cortisol response is a good thing. However, this "fight or flight" response is meant as a short-term reaction to a sudden stressor. People with long-term stress never get the signal to go back to normal and are not able to regulate or control their cortisol levels. As a result, the "fight or flight" response continues. Over time, this inability to regulate cortisol levels may lead to health problems all over the body, including:

  • Difficulty fighting off infections

  • Digestive issues like an upset stomach and heartburn

  • Increased risk of heart disease and heart attack due to high blood pressure and fast heart rate causing the heart to work harder

  • Trouble sleeping

  • Decreased interest in sex

  • Decreased overall mental health and increased risk of anxiety and depression

  • Memory problems

  • High blood sugar levels and weight gain

If your body produces too much or too little cortisol, this can lead to medical problems known as Cushing syndrome and adrenal insufficiency.

Cushing syndrome

Cushing syndrome is a medical condition caused by high levels of cortisol in the blood over a long period of time. It can be caused by exogenous (outside the body) or endogenous (inside the body) factors. The most common exogenous cause of Cushing syndrome is the long-term use of oral glucocorticoid (steroid) medications, like prednisone (Hormone Health Network, 2019).

Once you stop taking the steroid, the syndrome usually improves. Endogenous Cushing syndrome is most often caused by a tumor in the brain that secretes too much ACTH and causes the adrenal glands to release too much cortisol. Alternatively, a cortisol-producing tumor in the adrenal gland can have the same result. In these cases, surgically removing the tumor can improve the syndrome. Symptoms of Cushing syndrome include:

  • Weight gain, especially in the face, abdomen, and chest

  • Rounded face due to fat deposit on the side of the face (moon or cushingoid facies)

  • Elevated blood sugar (prediabetes and diabetes)

  • High blood pressure (hypertension)

  • Bone loss (osteoporosis)

  • Fatigue and muscle weakness

  • Thin, fragile skin 

  • Easy bruising

  • Purple or red stretch marks or striae (usually over the abdomen and under the arms)

  • Mood changes and difficulties sleeping

  • Increased facial hair in women (hirsutism)

  • Irregular menstrual periods

  • Erectile dysfunction

Adrenal insufficiency

Adrenal insufficiency is a medical condition characterized by adrenal glands making too little cortisol. In primary adrenal insufficiency, also called Addison's disease, the key problem is that the adrenal gland is not able to produce cortisol. Secondary adrenal insufficiency is when the pituitary gland in the brain does not make enough ACTH, thereby decreasing the necessary signal to the adrenal glands to trigger cortisol production.

The most common cause of adrenal insufficiency is stopping corticosteroid medications too rapidly after taking them for a long time. This is why it is important to slowly decrease (or taper) the dose of steroid drugs rather than stopping them abruptly (NIDDK, 2018). Symptoms of adrenal insufficiency include:

  • Fatigue, often long-lasting

  • Muscle weakness

  • Decreased appetite

  • Weight loss

  • Abdominal pain, nausea, vomiting, diarrhea

  • Low blood pressure, especially with you stand up (orthostatic hypotension) 

  • Joint pain

  • Low blood glucose (hypoglycemia)

  • Irregular menstrual periods

  • Decreased sexual desire

Managing cortisol levels

Sometimes, the only way to manage your cortisol levels is via medications or surgery. Your healthcare provider should discuss these options with you if that is the case. However, for some people, cortisol levels may be improved through natural remedies. Since cortisol increases in response to stress, taking steps to lower your stress may also help improve your cortisol levels. Some techniques to reduce stress include (NIMH, 2019):

  • Exercise

  • Eating a healthy diet

  • Relaxing activities like meditation, yoga, and breathing exercises

  • Scheduling time for yourself to participate in a hobby, curl up with a good book, or just focus on yourself for a bit

  • Getting a good night's sleep

  • Seeking emotional support from family and friends

  • Avoiding smoking and drinking too much alcohol


If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

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Current version

February 20, 2020

Written by

Chimene Richa, MD

Fact checked by

Mike Bohl, MD, MPH, ALM

About the medical reviewer

Dr. Mike is a licensed physician and a former Director, Medical Content & Education at Ro.