PTH and osteitis fibrosa: Common indications for surgery include elevated levels of parathyroid hormone (PTH), hypercalcaemia (>2.6 mmol/L), hyperphosphataemia (>1.95 mmol/L), bone disease (osteitis fibrosa cystica on X-ray), severe symptoms (pruritus, malaise, bone pain), progressive ectopic calcification, and calciphylaxis [4].