Addison's Disease Presenting with Hypercalcaemia, Acute Kidney Injury, and Anxiety

This report describes the case of a 41-year-old woman who presented with Addison's disease, manifesting as hypercalcaemia, acute kidney injury, and anxiety. She experienced progressive weight loss, fatigue, vomiting, dizziness, and anxiety over three months. Initial laboratory investigations revealed parathyroid hormone (PTH)-independent hypercalcaemia and renal impairment. Imaging and biochemical screening excluded malignancy and other common causes of hypercalcaemia. Endocrine evaluation confirmed primary adrenal insufficiency (PAI), evidenced by markedly reduced morning cortisol, elevated adrenocorticotropic hormone (ACTH), and positive adrenal cortex antibodies. Treatment with intravenous fluids and hydrocortisone led to rapid normalisation of calcium and renal function, accompanied by significant improvement in psychiatric symptoms.