Addisons

Addison's disease, or primary adrenal insufficiency, is a disorder resulting from destruction or dysfunction of the adrenal cortex, leading to deficient production of cortisol and often aldosterone. In developed countries, autoimmune destruction is the most common cause; less common causes include infections such as tuberculosis, hemorrhage, metastatic disease, and genetic adrenal disorders.

Symptoms develop gradually and include fatigue, weight loss, poor appetite, nausea, abdominal pain, and salt cravings. Hyperpigmentation of the skin and mucous membranes can occur due to elevated ACTH. Low cortisol and aldosterone can cause low blood pressure, orthostatic dizziness, hyponatremia, hyperkalemia, and sometimes hypoglycemia. An acute adrenal crisis is a life-threatening emergency characterized by severe hypotension, dehydration, vomiting, abdominal pain, confusion, and shock.

Diagnosis is suspected from symptoms and confirmed with laboratory tests showing low morning cortisol with inappropriately high ACTH, and an inadequate response to the cosyntropin stimulation test. Baseline electrolytes often show hyponatremia and hyperkalemia; renin and aldosterone measurements may be used; imaging is reserved for evaluating underlying causes.

Treatment involves lifelong hormone replacement. Glucocorticoid replacement is typically hydrocortisone in divided doses; mineralocorticoid replacement with fludrocortisone is used if aldosterone deficiency is present. Patients are advised to increase the glucocorticoid dose during illness or stress (stress dosing) and to carry a medical alert. Adrenal crisis requires immediate emergency care with intravenous fluids and hydrocortisone.

With appropriate management, many individuals live normal lifespans. Regular follow-up, dose adjustments, vaccination considerations, and education about recognizing crises are essential. The condition is named after Thomas Addison, who first described it in the 19th century.