For Patients & General Readers

Addison's disease is a rare disorder where your adrenal glands don't produce enough essential hormones, primarily cortisol and aldosterone. This can lead to a range of symptoms like fatigue, weight loss, and skin darkening. Early diagnosis and lifelong hormone replacement therapy are crucial for managing this condition and preventing life-threatening complications.

Clinical Overview

Primary adrenal insufficiency, or Addison's disease, is characterized by the chronic insufficient production of glucocorticoids and often mineralocorticoids by the adrenal cortex. Autoimmune destruction is the most common etiology, leading to progressive adrenal gland failure and subsequent hormonal deficiencies.

Clinical Presentation

Gradual onset of fatigue and weakness
Unexplained weight loss and decreased appetite
Hyperpigmentation of skin and mucous membranes
Orthostatic hypotension and dizziness
Salt craving and gastrointestinal disturbances

Signs & Symptoms

Symptoms (Patient-Reported)

Persistent fatigue and lack of energy
Muscle weakness and joint pain
Unintentional weight loss
Loss of appetite
Nausea, vomiting, and diarrhea
Darkening of the skin (hyperpigmentation)
Craving for salt
Low blood pressure
Irritability and depression

Signs (Clinician-Observed)

Hyperpigmentation (especially in sun-exposed areas, creases, and buccal mucosa)
Hypotension, particularly orthostatic
Tachycardia
Vitiligo (in autoimmune Addison's)

Differential Diagnoses

Condition	Distinguishing Feature
Secondary Adrenal Insufficiency	Absence of hyperpigmentation and normal or elevated ACTH levels, as the pituitary is the primary site of dysfunction.
Chronic Fatigue Syndrome	Lack of specific hormonal deficiencies and characteristic hyperpigmentation; diagnosis of exclusion.
Hypothyroidism	Symptoms can overlap (fatigue, weight changes), but thyroid hormone levels will be abnormal, and cortisol levels will be normal unless co-existing adrenal insufficiency is present.
Anemia	Fatigue and pallor are common, but specific iron studies or B12/folate levels will be abnormal, and cortisol levels will be normal.
Gastroenteritis	Acute onset of GI symptoms, often infectious, with normal adrenal function tests.
Depression	Mood disturbances are primary, with normal hormonal profiles unless co-existing adrenal insufficiency is present.

Red Flags — Seek Immediate Care

Sudden onset of severe abdominal pain, vomiting, and dehydration (Addisonian crisis)
Profound weakness, confusion, or loss of consciousness
Fever in the context of known adrenal insufficiency
Hypotension unresponsive to standard fluid resuscitation

Key Investigations

Morning serum cortisol level (low)
Plasma ACTH level (high in primary, low in secondary)
Cosyntropin stimulation test (ACTH stimulation test) to assess adrenal reserve
Electrolytes (hyponatremia, hyperkalemia)
Renin and aldosterone levels (if mineralocorticoid deficiency is suspected)

Management Overview

Management involves lifelong hormone replacement therapy with glucocorticoids (e.g., hydrocortisone) and mineralocorticoids (e.g., fludrocortisone). Patients require education on stress dosing of glucocorticoids during illness or injury and carrying emergency hydrocortisone for Addisonian crises.

Disclaimer: This article is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for diagnosis and treatment. TruelyserMD does not replace clinical judgement.