What is cortisol and when is a test for this stress hormone prescribed?

What is cortisol and its functions in the body?

Cortisol is a hormone produced by the adrenal cortex and is involved in many processes in the body. Its main function is to help the body adapt to stress, mobilize energy resources, and regulate metabolism. Cortisol also affects the functioning of the cardiovascular and immune systems, controls blood glucose levels, and maintains water and salt balance.

The main functions of cortisol:

• increasing glucose levels to provide the body with energy;
• blood pressure regulation;
• control of protein, fat and carbohydrate metabolism;
• suppression of inflammatory processes;
• impact on emotional state and level of stress resistance.

The level of cortisol in the body naturally varies throughout the day: it is highest in the morning hours (when the body is activated), and lowest in the evening, which helps prepare for sleep.

When is a cortisol test prescribed: main indications

Referrals for cortisol levels are most often given by an endocrinologist, internist, cardiologist, or gynecologist. The test is prescribed in the following cases:

• Suspicion of Cushing's syndrome (hypercorticism): rapid weight gain (especially in the face and abdomen), purple stretch marks (striae) on the skin, muscle weakness, brittle bones.
• Suspicion of Addison's disease (adrenal insufficiency): chronic fatigue that does not go away after rest, constantly low blood pressure, loss of appetite, darkening of the skin (hyperpigmentation).
• Persistent arterial hypertension: high blood pressure that is difficult to treat with standard medications, especially at a young age.
• Endocrine infertility and menstrual irregularities (cortisol imbalance can suppress the reproductive system).
• Early puberty or developmental delay in children.

Important for diagnosis: A single blood test does not always give a complete picture due to daily hormone fluctuations. At the Medi Lab Plus medical center, a comprehensive assessment is often recommended: blood sampling in the morning and evening, as well as determination of cortisol in urine or saliva.

Cortisol levels in the blood

Normal values depend on the time of day and the individual characteristics of the body.

Deviations from these values may be caused by stress, hormonal disorders, or pathology of the adrenal or pituitary glands.

Real cases of cortisol level abnormalities

Example 1: Elevated cortisol levels due to chronic stress

Patient: Olga, 34 years old, manager.

Complaints: constant fatigue, anxiety, insomnia, weight gain in the abdominal area.

Results: morning cortisol — 750 nmol/l (above normal).

Reason: chronic stress and disruption of the daily routine.

Correction: Regular exercise, meditation, reducing caffeine, and normalizing sleep helped bring the indicator back to normal within three months.

Example 2: Excess cortisol due to Cushing's syndrome

Patient: Andriy, 45 years old.

Symptoms: central obesity, high blood pressure, muscle weakness.

Results: morning cortisol — 890 nmol/l, elevated level cortisol in urine.

Reason: Cushing's syndrome.

Correction: Drug treatment and adrenal gland monitoring allowed the hormone level to be reduced to 550 nmol/l within six months.

Example 3: Low cortisol levels and adrenal insufficiency

Patient: Marina, 29 years old.

Complaints: constant weakness, low blood pressure, dizziness.

Results: morning cortisol — 95 nmol/l (below normal).

Reason: secondary adrenal insufficiency associated with pituitary dysfunction.

Correction: Diet, hormone replacement therapy, and normalization of daily routine allowed the hormone levels to be restored within three months.

Causes of elevated cortisol

• prolonged stress and emotional overstrain;
• chronic sleep deprivation;
• Cushing's syndrome and other hormonal disorders;
• excessive use of caffeine and stimulants;
• too intense training without recovery.

Causes of low cortisol

• Addison's disease;
• pituitary dysfunction;
• adrenal insufficiency;
• abrupt withdrawal of glucocorticoid drugs;
• cholesterol deficiency (material for hormone synthesis).

How to prepare for a cortisol test

For accurate results, it is important to follow the preparation rules:

• avoid intense physical exertion and severe stress for 24 hours;
• exclude coffee, tea, and alcohol for 12 hours;
• do not eat for 8 hours;
• Do not smoke 2 hours before donating blood.

How to normalize cortisol levels

Normalization requires a comprehensive approach: lifestyle changes, nutrition, and, if necessary, medication.

Methods for reducing cortisol

• moderate regular physical activity;
• yoga, meditation, stress reduction techniques;
• sleep at least 7–8 hours a day;
• refusal or significant reduction of caffeine;
• foods rich in magnesium and B vitamins.

Methods to increase cortisol

• balanced diet with enough protein and healthy fats;
• control of sodium and potassium balance;
• adaptogens (ginseng, rhodiola rosea - on the recommendation of a doctor).

Regular monitoring of cortisol levels helps prevent many chronic diseases and significantly improves the quality of life. If you experience symptoms of hormonal imbalance, be sure to consult a doctor.

Author: Ulyana Anatolyivna Dzyuba

Director of Medi Lab Plus LLC, a doctor of the highest category. Has over 45 years of practical experience in medicine and laboratory diagnostics. Founder and head of the laboratory since 2007. More details…