The adrenal glands, small triangular organs perched on top of each kidney, play a monumental role in maintaining balance within the human body. By secreting hormones that regulate metabolism, stress response, immune function, and electrolyte balance, the adrenal cortex ensures the body’s survival under both normal and stressful conditions. Disorders of the adrenal cortex, particularly Cushing’s Syndrome and Addison’s Disease, represent two ends of the hormonal spectrum: one caused by excess steroids and the other by deficiency.
Understanding the Adrenal Cortex and Its Hormones
The adrenal cortex produces three essential categories of hormones:
- Glucocorticoids (Cortisol): Regulate metabolism, immune function, and the body’s stress response.
- Mineralocorticoids (Aldosterone): Control sodium and water retention, potassium excretion, and blood pressure regulation.
- Sex Hormones (Androgens): Contribute to secondary sexual characteristics and libido.
A well-functioning adrenal cortex ensures stability of electrolytes, energy metabolism, and overall stress management. Any imbalance can lead to systemic complications, making these disorders clinically significant.
Cushing’s Syndrome: The “Cushion” of Excess Steroids
Cushing’s syndrome is a disorder caused by too much cortisol in the body, either due to internal overproduction or external administration of steroid medications. It is often remembered by the phrase, “They have a cushion,” symbolizing excess storage of fat and hormones.
Causes of Cushing’s Syndrome
- Prolonged use of corticosteroid medications (iatrogenic Cushing’s)
- Adrenal gland tumors secreting cortisol
- Pituitary adenomas causing Cushing’s disease through excess ACTH secretion
- Ectopic ACTH production from non-pituitary tumors
- More common in females than males
Signs and Symptoms
Patients with Cushing’s syndrome develop characteristic physical and metabolic changes:
Musculoskeletal changes: Muscle wasting, weakness, and thin extremitiesMetabolic imbalances:
- High glucose (hyperglycemia)
- High sodium (Na⁺ retention)
- Low potassium (hypokalemia)
- Low calcium
Treatment of Cushing’s Syndrome
- Adrenalectomy in cases of adrenal tumors
- Lifelong glucocorticoid replacement therapy after adrenal removal
- Gradual withdrawal of corticosteroid therapy (if drug-induced)
- Chemotherapy or radiation for adrenal or pituitary tumors
- Infection prevention due to immunosuppression
Addison’s Disease: The “Addition” of Missing Steroids
Addison’s disease is the clinical result of inadequate secretion of adrenal cortex hormones, most notably cortisol and aldosterone. The mnemonic, “We need to add some,” reflects the need for hormone replacement in this disorder.
Causes of Addison’s Disease
- Surgical removal of adrenal glands
- Infections such as tuberculosis, HIV, or cytomegalovirus
- Autoimmune destruction of adrenal tissue
- Metastatic cancer infiltration into the adrenal glands
- Adrenal hemorrhage (e.g., Waterhouse-Friderichsen syndrome)
Signs and Symptoms
Addison’s presents with features directly opposite to Cushing’s:
Fatigue and weaknessHypoglycemia (low blood sugar)
Electrolyte imbalance:
- Low sodium (hyponatremia)
- Low water retention → dehydration
- High potassium (hyperkalemia)
Addisonian Crisis
An acute, life-threatening emergency, Addisonian crisis is marked by:
- Profound fatigue
- Severe dehydration and shock
- Renal failure
- Vascular collapse
- Hyponatremia and hyperkalemia
Management includes:
- Rapid fluid resuscitation
- High-dose intravenous hydrocortisone
Treatment of Addison’s Disease
- Glucocorticoid and mineralocorticoid replacement therapy
- High-protein and carbohydrate diet
- Education about stress-dose steroids during illness or surgery
Key Differences Between Cushing’s Syndrome and Addison’s Disease
| Feature | Cushing’s Syndrome (Excess Steroids) | Addison’s Disease (Deficient Steroids) |
|---|---|---|
| Hormone levels | High cortisol, high aldosterone | Low cortisol, low aldosterone |
| Appearance | Moon face, buffalo hump, truncal obesity | Weight loss, muscle weakness, hyperpigmentation |
| Blood pressure | Hypertension | Hypotension |
| Glucose levels | Hyperglycemia | Hypoglycemia |
| Sodium & Potassium | High Na⁺, Low K⁺ | Low Na⁺, High K⁺ |
| Skin | Thin skin, striae, bruising | Hyperpigmentation, vitiligo |
| Emergency | Cushing’s rarely causes crisis | Addisonian crisis is life-threatening |
Diagnosis of Adrenal Cortex Disorders
Diagnosis requires a combination of clinical suspicion, biochemical tests, and imaging.
For Cushing’s Syndrome:
- 24-hour urinary free cortisol
- Dexamethasone suppression test
- Plasma ACTH levels
- CT/MRI of adrenal or pituitary gland
- Morning cortisol and ACTH levels
- ACTH stimulation test
- Electrolyte panel
- Autoantibody screening
- CT scan of adrenal glands
Living with Adrenal Disorders
Both Cushing’s and Addison’s require lifelong management strategies. While treatments differ, patient education is critical.
- Cushing’s patients should be monitored for metabolic complications like diabetes, hypertension, and osteoporosis.
- Addison’s patients must learn stress-dosing techniques and carry medical alert identification to prevent crisis.
Frequently Asked Questions (FAQ)
Q1. What is the main difference between Cushing’s Syndrome and Addison’s Disease?
Cushing’s results from excess cortisol, while Addison’s stems from cortisol deficiency.
Q2. Can Addison’s Disease be cured?
Addison’s cannot be permanently cured but can be effectively managed with lifelong hormone replacement.
Q3. Why does Cushing’s cause a “moon face” and “buffalo hump”?
Excess cortisol redistributes fat to the face, upper back, and trunk, creating these classical features.
Q4. What triggers Addisonian Crisis?
It can be triggered by infections, trauma, surgery, or sudden withdrawal of steroids in an Addison’s patient.
Q5. Is Cushing’s Syndrome reversible?
Yes, if caused by medications or treatable tumors, symptoms can be reversed with proper treatment.
Q6. How can patients with Addison’s Disease prevent emergencies?
By adhering to medication schedules, adjusting steroid doses during stress, and keeping an emergency hydrocortisone injection kit.
