Hormone

Addison's Disease: Complete Guide

Addison's disease causes insufficient cortisol and aldosterone production. Recognising symptoms and managing adrenal crisis correctly can be life-saving.

Most common cause
Autoimmune adrenal destruction
Key test
Short synacthen (ACTH stimulation) test
Emergency
Adrenal crisis — life-threatening
Treatment
Lifelong steroid replacement

Symptoms

Diagnostic Tests

TestPurpose
Morning cortisolLow level supports diagnosis
Short synacthen testGold standard — cortisol measured before and after synthetic ACTH injection; failure to rise confirms adrenal insufficiency
ACTH levelHigh in primary adrenal failure (Addison's); low in secondary (pituitary) causes
Adrenal antibodiesConfirms autoimmune cause
ElectrolytesLow sodium, high potassium common

Adrenal Crisis — Life-Threatening Emergency

Adrenal crisis occurs when cortisol demand exceeds supply, often triggered by illness, injury, or surgery in someone with adrenal insufficiency. It causes severe low blood pressure, vomiting, and can be fatal without immediate emergency hydrocortisone injection.
Adrenal Crisis — Medical EmergencySevere weakness, vomiting, abdominal pain, confusion, and very low blood pressure in someone with known or suspected Addison's disease requires an emergency hydrocortisone injection immediately, followed by urgent hospital treatment — every person with Addison's should carry an emergency injection kit.
Sick Day RulesPeople with Addison's disease must double or triple their usual steroid dose during illness, fever, or injury ('sick day rules'), as the body cannot mount its own stress response. Always carry a steroid emergency card and medical alert bracelet.
Can Addison's disease be cured?
No — it requires lifelong steroid hormone replacement (hydrocortisone and often fludrocortisone), but with correct treatment, people with Addison's disease can live full, normal lives.
Is Addison's disease the opposite of Cushing's syndrome?
In terms of cortisol levels, yes — Addison's involves cortisol deficiency while Cushing's involves cortisol excess, though the underlying causes and management are quite different.
Medical Disclaimer: This page is for general education only and does not replace professional medical advice. Always consult a qualified healthcare provider.