Skip to main content Skip to navigation

Serum Cortisol Test – Indications, Procedures, Results

Last updated: February 8, 2026 Medically reviewed by: RxHarun Orthopedic Specialist Doctor Reading time: 9 min read

The cortisol blood test measures the level of cortisol in the blood. Cortisol is a steroid (glucocorticoid) hormone produced by the adrenal gland. A serum cortisol test may help in the diagnosis of two fairly uncommon medical conditions: Cushing syndrome and Addison disease. The test also screens for other diseases that affect your pituitary and adrenal glands. It does so by measuring your blood level of a stress hormone called cortisol.

Cortisol can also be measured using a urine or saliva test.

How the Test is Performed

A blood sample is needed .

How to Prepare for the Test

Your doctor will likely have you do the test early in the morning. This is important, because cortisol level varies throughout the day.

You may be asked not to do any vigorous exercising the day before the test.

You may also be told to temporarily stop taking medicines that can affect the test, including:

  • Anti-seizure drugs
  • Estrogen
  • Human-made (synthetic) glucocorticoids, such as hydrocortisone, prednisone and prednisolone
  • Androgens

How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or slight bruising. This soon goes away.

Why the Test is Performed

The test is done to check for increased or decreased cortisol production. Cortisol is a glucocorticoid (steroid) hormone released from the adrenal gland in response to adrenocorticotropic hormone (ACTH). ACTH is a hormone released from the pituitary gland in the brain.

Cortisol affects many different body systems. It plays a role in:

  • Bone growth
  • Blood pressure control
  • Immune system function
  • Metabolism of fats, carbohydrates, and protein
  • Nervous system function
  • Stress response

Different diseases, such as Cushing syndrome and Addison disease , can lead to either too much or too little production of cortisol. Measuring blood cortisol level can help diagnose these conditions. It is also measured to evaluate how well the pituitary and adrenal glands are working.

Other conditions for which the test may be ordered include:

  • Acute adrenal crisis , a life-threatening condition that occurs when there is not enough cortisol
  • Sepsis , an illness in which the body has a severe response to bacteria or other germs
  • Low blood pressure

Normal Results

Normal values for a blood sample taken at 8 in the morning are 6 to 23 micrograms per deciliter (mcg/dL) or 165.53 to 634.52 nanomoles per liter (nmol/L).

Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or may test different specimens. Talk to your doctor about the meaning of your specific test results.

What Abnormal Results Mean

A higher than normal level may indicate:

  • Cushing disease , in which the pituitary gland makes too much ACTH because of excess growth of the pituitary gland or a tumor in the pituitary gland
  • Ectopic Cushing syndrome , in which a tumor outside the pituitary or adrenal glands makes too much ACTH
  • Tumor of the adrenal gland that is producing too much cortisol

A lower than normal level may indicate:

  • Addison disease, in which the adrenal glands do not produce enough cortisol
  • Hypopituitarism, in which the pituitary gland does not signal the adrenal gland to produce enough cortisol
  • Suppression of normal pituitary or adrenal function by glucocorticoid medicines including pills, skin creams, eye drops, inhalers, joint injections, chemotherapy

Risks

Veins and arteries vary in size from one person to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight but may include:

  • Excessive bleeding
  • Fainting or feeling lightheaded
  • Hematoma (blood accumulating under the skin)
  • Infection (a slight risk any time the skin is broken)

FAQ

What happens if serum cortisol is low?

  • Low levels of cortisol can cause weakness, fatigue, and low blood pressure. You may have more symptoms if you have untreated Addison’s disease or damaged adrenal glands due to severe stress, such as from a car accident or an infection. These symptoms include sudden dizziness, vomiting, and even loss of consciousness.

What does high cortisol feel like?

  • Some of the most common signs of high cortisol levels include weight gain — particularly around your stomach, upper back, and face. fatigue. getting sick often.

How do you fix cortisol levels?

Stressed? 10 Ways To Lower Your Cortisol Levels
  • Eat a whole-food, plant-based diet.
  • If needed, add supplements.
  • Take deep breaths.
  • Reduce your caffeine intake.
  • Get adequate sleep.
  • Exercise regularly.
  • Write in a journal.
  • Indulge in hobbies.

How does cortisol affect sleep?

  • Poor sleep, as a result of too much cortisol, inflates your sleep debt and deflates your next-day energy levels. Predictably, you aren’t feeling and functioning at your best. To worsen the issue, there is a cause-and-effect relationship between HPA axis dysfunction and certain sleep disorders.

What causes cortisol to rise?

  • As your body perceives stress, your adrenal glands make and release the hormone cortisol into your bloodstream. Often called the “stress hormone,” cortisol causes an increase in your heart rate and blood pressure. It’s your natural “flight or fight” response that has kept humans alive for thousands of years.

What are the symptoms of low cortisol?

Signs and symptoms may include:
  • Extreme fatigue.
  • Weight loss and decreased appetite.
  • Darkening of your skin (hyperpigmentation)
  • Low blood pressure, even fainting.
  • Salt craving.
  • Low blood sugar (hypoglycemia)
  • Nausea, diarrhea or vomiting (gastrointestinal symptoms)
  • Abdominal pain.

What are the symptoms of low cortisol levels?

  • The adrenal glands then don’t make enough cortisol. Mild symptoms may be seen only when a person is under physical stress. Other symptoms may include weakness, fatigue, and weight loss. You will need to take hormones to replace those that the adrenal glands are not making.

What foods raise cortisol levels?

  • Good sources include fatty fish, nuts, and seeds. Water. Dehydration has been linked to a temporary increase in cortisol levels, making it even more important to drink water throughout the day.

What foods reduce cortisol levels?

Some foods that may help to keep cortisol levels stable include:
  • dark chocolate.
  • bananas and pears.
  • black or green tea.
  • probiotics in food such as yogurt.
  • probiotics in foods containing soluble fiber.

Do high cortisol levels cause belly fat?

  • Cortisol, in turn, may have caused them to accumulate abdominal fat. Genetics, however, also play a role in shaping reactivity to stress, as well as body shape.” Lifestyle and age may also influence levels of abdominal fat. Smoking, alcohol, and lack of exercise all contribute to greater abdominal fat.

Can high cortisol make you tired?

  • Very often, fatigue can be seen in people who have too much cortisol as well as those who have less than normal amounts of the hormone. Importantly, other hormonal problems, such as thyroid or pituitary problems, could lead to fatigue.

What vitamins help reduce cortisol levels?

Research suggests these herbs and natural supplements might lower stress, anxiety and/or cortisol levels:
  • Ashwagandha.
  • Rhodiola.
  • Lemon balm.
  • Chamomile.

What supplements help high cortisol?

  • Ashwagandha has been shown to alleviate raised cortisol levels in stressed humans by up to 30% when taken routinely, and studies around the world have shown that adults who supplement with ashwagandha consistently over a 30-60 day period demonstrate significantly reduced stress levels compared with those who take a

How can you lower your cortisol levels?

  1. Modify your diet to eliminate cortisol-triggering foods.
  2. Take fish oil and ashwagandha supplements.
  3. Exercise regularly at a moderate intensity.
  4. Notice and reframe thoughts that make you stressed or anxious.
  5. Practice mindfulness and meditation.

What time of day is cortisol highest?

In the morning
  • In most people, cortisol levels are highest in the morning when they wake up and lowest around midnight. Your body also pumps out excess cortisol when you’re anxious or under intense stress, which can affect your health if the levels stay too high for too long.

Does exercise increase cortisol?

  • But without proper recovery, intense exercise can lead to elevated levels of cortisol in the bloodstream and heightened symptoms of physical stress, even when exercise is not being performed.

Does low cortisol cause joint pain?

  • The low cortisol response to stress is associated with musculoskeletal pain combined with increased pain sensitivity in young adults: a longitudinal cohort study.

Can low cortisol cause heart problems?

  • It was shown that these imbalances in blood cortisol may lead to a higher prevalence of coronary heart disease, major adverse coronary events, and increased mortality.

Can anxiety cause high cortisol levels?

  • As a result, emotional states such as anxiety might produce a more substantial elevation in cortisol in older adults.

Does cortisol cause weight gain?

Cortisol Can Lead to Weight Gain

  • While this process is essential for survival situations, it also increases your appetite. Additionally, elevated cortisol levels can cause cravings for sweet, fatty, and salty foods.

How can I test my cortisol levels at home?

  • A person can take these tests at home by providing a urine, blood, or saliva sample. Once a lab analyzes the test, people usually receive their results within a few days. Individuals should follow up on any test results with a healthcare professional. Test your cortisol level from home with LetsGetChecked.

How much magnesium should I take to reduce cortisol?

  • In these subjects, 17 mmol magnesium supplementation per day lowered serum cortisol levels and augmented venous O2 partial pressure leading to better performance. Recent studies indicated that magnesium intake should be at least 260 mg/day for male and 220 mg/day for female athletes (Nielsen and Lukaski, 2006).

Why do doctors test cortisol levels?

  • Why is the cortisol level test performed? The cortisol level test is used to check if your cortisol production levels are either too high or too low. There are certain diseases, such as Addison’s disease and Cushing’s disease, which affect the amount of cortisol your adrenal glands produce.

What exercises release cortisol?

  • In addition to yoga and Pilates, walking, slow jogging, swimming, and a variety of lower-intensity boutique fitness classes (like the Lit Method) are all great examples of cortisol-conscious workouts.

What are the symptoms of high cortisol?

What are the symptoms of high cortisol?
  • weight gain, mostly around the midsection and upper back.
  • weight gain and rounding of the face.
  • acne.
  • thinning skin.
  • easy bruising.
  • flushed face.
  • slowed healing.
  • muscle weakness

How can I reduce my cortisol weight?

  • There are numerous ways to help reduce cortisol levels and combat potential weight gain. The most effective methods include exercising, practicing mindful eating, ensuring sufficient sleep, and practicing meditation.

What are the symptoms of low cortisol?

  • Low levels of cortisol can cause weakness, fatigue, and low blood pressure. You may have more symptoms if you have untreated Addison’s disease or damaged adrenal glands due to severe stress, such as from a car accident or an infection. These symptoms include sudden dizziness, vomiting, and even loss of consciousness.

What are the symptoms of low cortisol levels?

Too Little Cortisol
  • Changes in your skin, like darkening on scars and in skin folds.
  • Being tired all the time.
  • Muscle weakness that grows worse.
  • Diarrhea, nausea, and vomiting.
  • Loss of appetite and weight.
  • Low blood pressure.

What foods reduce cortisol levels?

Some foods that may help to keep cortisol levels stable include:
  • dark chocolate.
  • bananas and pears.
  • black or green tea.
  • probiotics in food such as yogurt.
  • probiotics in foods containing soluble fiber.

Can too much exercise increase cortisol?

  • But without proper recovery, intense exercise can lead to elevated levels of cortisol in the bloodstream and heightened symptoms of physical stress, even when exercise is not being performed.

What foods raise cortisol levels?

  • Eating foods such as processed meats, high sugar foods, caffeine and alcohol, which provide little nutritional value, have been associated with more psychiatric symptoms and can increase cortisol levels—our primary hormone responsible for stress,” she said.

Frequently Asked Questions

Is this article a replacement for a doctor?

No. It is educational content only. Patients should consult a qualified clinician for diagnosis and treatment.

When should I seek urgent care?

Seek urgent care for severe symptoms, rapidly worsening condition, breathing difficulty, severe pain, neurological changes, or any emergency warning sign.

References

Add references, clinical guidelines, textbooks, journal articles, or trusted medical sources here. You can edit this area later with a custom field named _rx_references.

Related Articles

Hemoglobin A1c Test

November 6, 202521 min read0 views

The hemoglobin A1c test—also known as glycated hemoglobin, glycosylated hemoglobin, HbA1c, or simply A1c—is used to measure an individual’s glucose control levels. The test shows average…

Read more

Orbital Decompression Surgery

August 18, 202518 min read0 views

Orbital decompression is an operation to make more room inside the eye socket. The eye socket is called the “orbit.” It is a cone-shaped…

Read more

Olfactory Nerve Disorders

May 8, 20248 min read0 views

Olfactory nerve disorders affect our sense of smell. This can impact our ability to enjoy food, detect danger like gas leaks, or even notice…

Read more

Written by Dr. Harun Ar Rashid, MD - Arthritis, Bones, Joints Pain, Trauma, and Internal Medicine Specialist

Dr. Md. Harun Ar Rashid, MPH, MD, PhD, is a highly respected medical specialist celebrated for his exceptional clinical expertise and unwavering commitment to patient care. With advanced qualifications including MPH, MD, and PhD, he integrates cutting-edge research with a compassionate approach to medicine, ensuring that every patient receives personalized and effective treatment. His extensive training and hands-on experience enable him to diagnose complex conditions accurately and develop innovative treatment strategies tailored to individual needs. In addition to his clinical practice, Dr. Harun Ar Rashid is dedicated to medical education and research, writing and inventory creative thinking, innovative idea, critical care managementing make in his community to outreach, often participating in initiatives that promote health awareness and advance medical knowledge. His career is a testament to the high standards represented by his credentials, and he continues to contribute significantly to his field, driving improvements in both patient outcomes and healthcare practices. Born and educated in Bangladesh, Dr. Rashid earned his BPT from the University of Dhaka before pursuing postgraduate training internationally. He completed his MD in Internal Medicine at King’s College London, where he developed a special interest in inflammatory arthritis and metabolic bone disease. He then undertook a PhD in Orthopedic Science at the University of Oxford, conducting pioneering research on cytokine signaling pathways in rheumatoid arthritis. Following his doctoral studies, Dr. Rashid returned to clinical work with a fellowship in interventional pain management at the Rx University School of Medicine, refining his skills in image-guided joint injections and minimally invasive pain-relief techniques.