What is the most common cause of primary adrenal insufficiency in industrialized countries?

• A. Autoimmune destruction of the adrenal cortex
• B. Infectious TB
• C. Vascular hemorrhage
• D. Metastatic disease

Answer: (A)

Autoimmune destruction of the adrenal cortex is the most common cause of primary adrenal insufficiency in industrialized countries. The immune system targets and progressively loses adrenal cortical tissue, leading to deficient production of cortisol and aldosterone. This results in fatigue, weight loss, nausea, low blood pressure, hyponatremia, and hyperkalemia; high ACTH can cause hyperpigmentation. Autoimmune Addison disease is often part of broader autoimmune tendencies and tends to be chronic and gradual in onset.

In contrast, infectious tuberculosis of the adrenals used to be a leading cause elsewhere but is now relatively rare in developed nations. Vascular hemorrhage typically triggers an acute, crisis-type adrenal failure in settings of severe sepsis or DIC, not the chronic autoimmune pattern seen here. Metastatic disease can involve the adrenals but is not the most common cause of chronic primary adrenal insufficiency in these populations.