Contributed by – Healthians Team

What is the Serum Cortisol test?

Serum cortisol test measures the level of cortisol in your blood.  Cortisol is popularly known as the ‘stress hormone’ because stress triggers cortisol secretion. When a stressful event occurs, our bodies release a flood of cortisol preparing the body for fight or flight. It is an important and powerful hormone that affects almost every organ in your body. It plays an important role in many bodily functions like:

  • Responding to stressors
  • Fighting infection
  • Regulating blood glucose
  • Maintaining blood pressure
  • Regulating metabolism and immune response
  • Influencing memory consolidation

Cortisol is produced and secreted by your adrenal glands, two small glands that sit above the kidneys. Cortisol plays a key role in your body’s response to stressful situations and low blood glucose concentration. Keeping blood cortisol levels even is important for the body to survive and thrive. But it’s also more than that! Cortisol inhibits the release of oxytocin, the ‘love hormone’ or ‘cuddle chemical’ that helps us forge connections with other people and makes us empathetic and generous.

A blood test is the most common way of measuring cortisol. Let’s have a look at the purpose of the cortisol test, its procedure, and the results.


Who should get a Serum Cortisol test?

Your doctor may order a cortisol test if they see symptoms that suggest your levels are either too high or too low. This condition may be an indication of problems with your adrenal glands.

High Cortisol Levels Symptoms and Signs

  • Fatigue
  • Mid-section weight gain
  • Bruising easily
  • Swelling in the legs
  • Mood swings
  • Irregular periods

Low Cortisol Levels Symptoms and Signs

  • Extreme fatigue
  • Weight loss and decreased appetite
  • Darkening of skin
  • Low blood pressure
  • Salt craving
  • Low blood sugar
  • Gastrointestinal symptoms
  • Abdominal pain

You may also need a cortisol test if you exhibit signs and symptoms of an adrenal crisis. This disorder can be serious if not treated and can happen when your cortisol levels are extremely low. Symptoms of an adrenal crisis include:

  • Very low blood pressure
  • Severe vomiting
  • Severe diarrhoea
  • Dehydration
  • Sudden and severe pain in the abdomen, lower back, and legs
  • Confusion
  • Loss of consciousness

You may also get the test done if you have concerns about stress or its effects on your health.


Why is the Serum Cortisol test needed?

A serum cortisol test may be needed in the diagnosis of two fairly uncommon medical conditions:

  • Cushing syndrome, a disorder which involves having too much of the hormone
  • Addison disease, a disorder which involves having too low of the hormone

The test also screens for other diseases that affect your pituitary and adrenal glands.


What does a Serum Cortisol test result mean?

Serum Cortisol (nmol/L) Normal Range (nmol/L)
8 am, 766 171-536
6 pm, 732 64-327


Higher than normal results

Abnormally high cortisol levels in the body indicate that you have Cushing syndrome or another disorder of unbalanced hormones.

Lower than normal results

Abnormally low cortisol levels in the body indicate that you have Addison disease or another type of adrenal disease.

How is the Serum Cortisol test done?

The test requires a simple blood test to ascertain the amount of cortisol in the blood. A needle is used to draw blood sample from the vein located on the inside of the elbow. Testing for cortisol levels doesn’t require you to fast. Stress can raise your cortisol levels. Therefore, you should rest adequately before the test. You will also need to avoid over-the-counter medications that can affect the results of the test.

The timing of a cortisol test is important. It is often administered twice in the same day — once in the morning, and again later in the afternoon, around 4 p.m. This is because cortisol levels vary from morning to day and night. So you may have to schedule two appointments at different times of the day.

Evaluate your Cortisol levels now!