Cortisol and Adrenal Glands: Symptoms of Disorders and When to Get Tested
Chronic fatigue that doesn't improve with rest, weight gain around the abdomen, mood swings, and a sense of being "wired" even at night — people often attribute all of this to stress. And they're partly right: behind many of these symptoms is cortisol — the body's primary stress hormone, produced by the adrenal glands. But sometimes similar complaints conceal serious conditions — Cushing's syndrome or Addison's disease. This article explains how the adrenal glands work, what happens when their function is disrupted, and when to see an endocrinologist.
What the adrenal glands do and why it matters
The adrenal glands are two small organs that sit on top of the kidneys. Despite their modest size (each weighing about 5–7 grams), they produce hormones without which normal life is impossible.
The adrenal cortex produces three groups of hormones:
- Glucocorticoids (the main one being cortisol) — regulate metabolism, immune response, stress reaction, blood glucose, and blood pressure.
- Mineralocorticoids (the main one being aldosterone) — regulate fluid and salt balance and blood pressure.
- Androgens — precursors to sex hormones.
The adrenal medulla produces adrenaline and noradrenaline — the hormones of acute stress ("fight or flight").
Cortisol follows a daily rhythm: its level peaks in the morning (6–8 am), helping the body wake up and start the day, and is at its lowest at night. Disruption of this rhythm is one of the first signs of adrenal dysfunction.
High cortisol: symptoms of chronic stress and Cushing's syndrome
Cortisol rises with any stress — physical or psychological. This is a normal protective response. The problem arises when cortisol is chronically elevated — either from persistent stress or from a tumour of the adrenal glands or pituitary gland (Cushing's syndrome).
Symptoms of chronically high cortisol:
- central obesity — fat accumulates on the abdomen, back, and face ("moon face"), while the arms and legs may remain thin;
- a fatty hump on the back of the neck ("buffalo hump");
- stretch marks (striae) — wide, purple, most often on the abdomen, thighs, and armpits;
- thinning and fragile skin, tendency to bruise easily;
- muscle weakness, especially in the legs (difficulty climbing stairs);
- elevated blood pressure;
- irregular menstrual cycles in women;
- reduced libido, erectile dysfunction in men;
- sleep disturbances — difficulty falling asleep, early waking;
- anxiety, irritability, depression;
- elevated blood glucose (steroid diabetes);
- osteoporosis — cortisol breaks down bone tissue when chronically elevated.
Cushing's syndrome is a rare condition (5–6 cases per million per year) in which cortisol is chronically and significantly elevated due to a tumour. The most common cause is a pituitary adenoma (Cushing's disease) or an adrenal tumour. Cushing's syndrome also develops with long-term use of high-dose glucocorticoid medications (prednisolone, dexamethasone) — this is called iatrogenic Cushing's syndrome.
Important: many symptoms of high cortisol are non-specific and occur in other conditions. Diagnosis is made only through laboratory testing.
Low cortisol: Addison's disease and adrenal fatigue
Adrenal insufficiency is a condition in which cortisol is produced in insufficient amounts. It can be primary (Addison's disease — damage to the adrenal glands themselves) or secondary (disrupted regulation from the pituitary gland).
Symptoms of Addison's disease:
- profound chronic fatigue that does not improve with rest;
- muscle weakness;
- weight loss and reduced appetite;
- low blood pressure, dizziness on standing;
- craving for salty foods;
- skin darkening (hyperpigmentation) — especially on exposed areas, skin folds, and mucous membranes (a characteristic sign of primary adrenal insufficiency);
- nausea, abdominal pain;
- depression, irritability.
Addisonian crisis — acute adrenal insufficiency — is a life-threatening emergency. Signs: sudden severe weakness, vomiting, abdominal pain, sharp drop in blood pressure, loss of consciousness. Requires immediate medical attention.
It is worth mentioning the popular but medically unrecognised term "adrenal fatigue". It describes chronic fatigue, reduced capacity for work, and other symptoms supposedly caused by adrenal "exhaustion" from stress. There is no scientific evidence for this as an independent diagnosis. If you have such symptoms, it is important to rule out real conditions (hypothyroidism, anaemia, depression, adrenal insufficiency) through testing.
Cortisol reference ranges and when to get tested
Cortisol has a pronounced daily rhythm, so the timing of the test is critically important.
Blood cortisol reference ranges:
- Morning (8:00–9:00 am): 171–536 nmol/L (62–194 ng/mL);
- Evening (4:00–6:00 pm): approximately half the morning level — around 85–268 nmol/L;
- Night (11:00 pm–midnight): should be at its lowest — below 50 nmol/L.
Reference ranges may vary slightly between laboratories. Important: a single test is minimally informative — cortisol responds to any stress, including the act of having blood drawn. Several methods are therefore used for diagnosis:
- 24-hour urine free cortisol — reflects total production over 24 hours, less subject to situational fluctuations.
- Late-night salivary cortisol (11:00 pm) — highly sensitive for Cushing's syndrome (should be very low at night).
- Low-dose dexamethasone suppression test — taking 1 mg of dexamethasone at night and measuring cortisol in the morning. Normally, cortisol is suppressed to below 50 nmol/L. If not — this is a sign of autonomous cortisol production (possible Cushing's syndrome).
- ACTH (adrenocorticotropic hormone) — helps distinguish primary from secondary adrenal insufficiency.
If you're experiencing the symptoms described above, try describing them to our assistant — this helps organise your complaints before a doctor's visit.
When to see an endocrinologist
See an endocrinologist if you have:
- characteristic fat distribution (abdomen, face, neck) with thin limbs;
- wide purple stretch marks;
- unexplained chronic fatigue combined with low blood pressure and salt craving;
- skin darkening without obvious cause;
- elevated blood pressure and blood glucose without clear reason in a young person;
- an incidentally discovered adrenal mass (incidentaloma) on ultrasound or CT scan.
To find the right specialist, use the doctor routing tool.
Frequently asked questions
Can cortisol be lowered without medication?
With a functional rise in cortisol due to chronic stress — yes. Regular sleep (7–9 hours), moderate physical activity, stress management techniques (meditation, breathing exercises), and limiting caffeine and alcohol reduce baseline cortisol levels. With Cushing's syndrome or Addison's disease, self-treatment is not appropriate — medical care is required.
What is an adrenal incidentaloma?
An incidentaloma is an adrenal mass discovered incidentally on ultrasound, CT, or MRI performed for another reason. It occurs in 1–5% of people. Most incidentalomas are benign and hormonally inactive. But some produce hormones (cortisol, aldosterone, catecholamines). Therefore, when an incidentaloma is found, an endocrinologist consultation and hormonal workup are mandatory.
Does stress really "burn out" the adrenal glands?
No. Chronic stress does not destroy the adrenal glands. It can disrupt the cortisol rhythm and cause symptoms resembling adrenal dysfunction. But true adrenal insufficiency (Addison's disease) is most often autoimmune in origin or related to tuberculosis, tumours, or haemorrhage.
Should cortisol be tested for chronic fatigue?
It is one of the tests worth including in an evaluation for unexplained chronic fatigue — alongside TSH (thyroid), full blood count, ferritin (iron stores), vitamin D, and vitamin B12. A single cortisol measurement is minimally informative — correct interpretation requires attention to the time of sampling and the clinical picture.
How does cortisol relate to weight gain?
Chronically elevated cortisol promotes accumulation of visceral fat (around the abdomen), increases appetite and cravings for calorie-dense foods, and reduces insulin sensitivity. This explains why people under chronic stress often gain weight, particularly around the abdomen, even without changes in their diet.
Symptomatica is an informational reference service. Not a medical service; does not diagnose or prescribe treatment. For any symptoms, please consult a doctor.