Thiazide diuretics and primary hyperparathyroidism.

Thiazide diuretics exert a natriuretic and diuretic effect by inhibiting sodium reabsorption in the distal convoluted tubule. Furthermore, thiazide diuretics affect renal calcium handling by increasing calcium reabsorption, leading to hypocalciuria. The effect that thiazide diuretics exert on parathyroid hormone secretion is controversial.

Immobilisation hypercalcaemia.

Hypercalcaemia is a common metabolic abnormality and its differential diagnosis is vast. Immobility is an uncommon cause of hypercalcaemia. Immobilisation hypercalcaemia is independent of parathyroid hormone and is associated with low levels of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D.

Lithium-associated hyperparathyroidism.

Lithium is a mood stabiliser widely used in the treatment and prophylaxis of mania, bipolar disorders and recurrent depression. Treatment with lithium can give rise to various endocrine and metabolic abnormalities, including thyroid dysfunction, nephrogenic diabetes insipidus and hypercalcaemia. Lithium may induce hypercalcaemia through both acute and chronic effects.