[Case of clinically "aggressive" course of primary hyperparathyroidism, algorithm of differential diagnosis].

Primary hyperparathyroidism (PHPT) is a significant endocrine disease caused by increased production of parathyroid hormone (PTH) by altered parathyroid glands and violation of the mechanisms of regulation of serum calcium concentrations. These changes can lead to nephrolithiasis, osteoporosis, erosive and ulcerative lesions of the gastrointestinal tract, a number of less specific symptoms (nausea, vomiting, weakness, fatigue, etc.).