Have you heard of the stress hormone? It is called cortisol. As an essential hormone, cortisol is made by the adrenal glands sitting atop the kidneys. It is called the stress hormone because cortisol levels rise in response to stress.
Apart from dealing with stress, cortisol is responsible for the regulation of critical activities in the body. It includes blood sugar concentration, blood pressure, energy balance, and metabolism. In case cortisol action is impaired, the body is unable to stabilise itself when stressed physically or emotionally.
What is cortisol, and why is it important?
Corisol is a steroid hormone. When cortisol levels are too high or too low, huge health problems can arise. Excess cortisol may induce weight gain, high blood pressure, anxiety, and sleep disturbance, whereas low cortisol can cause fatigue, muscle weakness, and hypotension. Hence, cortisol levels must be kept in balance to ensure health, hormonal balance, and well-being.
What is a cortisol test?
A cortisol test is the name given to a medical investigation in which the level of cortisol in a person is measured. Because the stimulus level is supposed to change throughout the day, the test, therefore, is used by physicians to judge whether the adrenal glands are functioning well. The cortisol test may indicate if the body is producing an overabundance of hormone (which may point toward Cushing's syndrome) or too little hormone (which may point toward Addison's disease or adrenal insufficiency).
The test is often recommended by doctors when there is unexplained fatigue, weight increase or decrease, hypertension, or hormonal alteration. The obtained test can be that which is analysed in blood, a 24-hour collection of urine, or a saliva sample, depending on the disorder being analysed. Stress-related and endocrine disorders can be identified early by cortisol tests, as they are widely used in differential diagnosis.
Also read: Cortisol and weight gain: Know how elevated hormonal levels can increase your body weight
Types of cortisol tests
1. Cortisol blood test
This is the most typical test. A sample of blood is drawn from a vein in your arm to test for cortisol levels.
2. Serum cortisol test
This test counts the actual concentration of cortisol in the blood serum. It's usually performed in the morning when cortisol is most elevated.
3. Morning cortisol test
Cortisol levels are highest normally in the morning (6 am–8 am). Physicians might order a morning cortisol test for the best reading.
4. ACTH stimulation test
The test measures your adrenal glands' response to adrenocorticotropic hormone (ACTH). It diagnoses adrenal insufficiency and pituitary disease.
5. Saliva and urine cortisol tests
Saliva tests are more commonly used to test cortisol at night when it should be lowest. A 24-hour urine test indicates total production of cortisol in a day. They are used more and more to find hidden adrenal disease.
Why physicians order cortisol level tests
Physicians may recommend a test of cortisol levels if you are having:
- Unexplained fatigue or weakness
- Weight gain or loss that is not explained
- Irregular periods or infertility
- Constant stress, anxiety, or depression
- High blood pressure that is not responding to treatment
- Symptoms of Addison's disease or Cushing syndrome
Procedure for and timing of the cortisol test
Preparation: You might have to stop taking some medications (such as steroids) beforehand. Always take your doctor's advice.
- Blood sample: From a vein in your arm, typically in the morning.
- Test time: The test itself takes a few minutes.
- Timing: Cortisol is most elevated in the morning and lowest at midnight. Physicians often suggest a morning test or can order several samples over the course of the day.
Normal range of cortisol test results
Cortisol concentrations change with the time of day. Normal ranges are:
| Morning (6–8 am) | 5 to 23 mcg/dL |
| Afternoon (approximately 4 pm) | 3 to 13 mcg/dL |
| Night (midnight) | Less than 5 mcg/dL |
Values can vary marginally based on the lab. Always interpret with your physician.
Price and cost of the cortisol test in India
Prices for the cortisol test vary with labs and cities in India. The following is an approximate range:
| Test type | Price range |
| Serum cortisol test | Rs 500 – 900 |
| Morning cortisol test | Rs 600 – 1,000 |
| ACTH stimulation test | Rs 1,500 – 3,000 |
| 24-hour urine test | Rs 800 – 1,200 |
| Saliva cortisol test | Rs 700 – 1,200 |
(Prices may vary by location and diagnostic center)
Conditions diagnosed by the cortisol test
1. Cushing syndrome
Caused by excess cortisol, leading to weight gain, a round face, high blood sugar, and high blood pressure.
2. Addison’s disease
Caused by low cortisol levels, leading to fatigue, weight loss, dark skin patches, and low blood pressure.
3. Stress and adrenal disorders
Chronic stress or pituitary gland problems can also affect cortisol balance.
FAQs on cortisol testing
Is blood test enough to check cortisol?
Yes, but sometimes saliva or urine tests are also needed for a complete picture.
How to prepare for cortisol test?
Avoid stress, follow your doctor’s advice, and do not eat or take certain medicines (like steroids) before the test.
Can I do a cortisol test at home?
Yes, at-home cortisol test kits are available for saliva and urine samples. However, blood tests usually need to be done in a lab.
Disclaimer: Tips and suggestions mentioned in the article are for general information purposes only and should not be construed as professional medical advice. Always consult your doctor or a dietician before starting any fitness programme or making any changes to your diet.