Laboratory diagnosis of primary hyperparathyroidism in patients with nephrolithiasis

Primary hyperparathyroidism (PHPT) is a common endocrine disorder characterized by inappropriate secretion of parathyroid hormone (PTH), resulting in hypercalcemia and disturbances in calcium-phosphate metabolism. Nephrolithiasis represents one of the most frequent and clinically significant renal manifestations of the disease and may serve as an early indicator of PHPT. This review summarizes the current diagnostic approach to PHPT in patients presenting with nephrolithiasis, with particular emphasis on laboratory evaluation. Key biochemical parameters, including serum calcium, ionized calcium, parathyroid hormone, phosphate, vitamin D status, and urinary calcium excretion, are discussed in the context of diagnosis, differential diagnosis, and postoperative follow-up. Special attention is given to the differentiation between PHPT, familial hypocalciuric hypercalcemia, and secondary hyperparathyroidism. In addition, the review outlines the complementary role of imaging modalities in preoperative localization and discusses the indications for parathyroidectomy in patients with renal involvement. An integrated clinical, laboratory, and imaging approach is essential for accurate diagnosis, risk stratification, and individualized management of patients with PHPT-associated nephrolithiasis.