Primary hyperparathyroidism

Primary hyperparathyroidism is caused by excess secretion of PTH resulting in hypercalcaemia. It is the most common cause of hypercalcaemia in outpatients and is often diagnosed following an incidental finding of an elevated serum calcium concentration. In 85% of cases a parathyroid adenoma is responsible.

Causes of primary hyperparathyroidism

• 85%: solitary adenoma
• 10%: hyperplasia
• 4%: multiple adenoma
• 1%: carcinoma

Around 80% of patients are asymptomatic and are diagnosed on routine blood tests. The symptomatic features of primary hyperparathyroidism may be remembered by the mnemonic: 'bones, stones, abdominal groans and psychic moans':

• polydipsia, polyuria
• depression
• anorexia, nausea, constipation
• peptic ulceration
• pancreatitis
• bone pain/fracture
• renal stones
• hypertension

Associations

• hypertension
• multiple endocrine neoplasia: MEN I and II

Investigations