Differential diagnosis of polyuria: Clinical cases and literature review

Abstract

Polyuria can be a symptom of various conditions, such as diabetes mellitus, diabetes insipidus, chronic tubulointerstitial nephritis, or primary polydipsia. Effective management of polyuria requires a thorough differential diagnosis, incorporating clinical, laboratory, and instrumental evaluations to identify its underlying cause.

The paper presents two clinical cases focused on the differential diagnosis of polyuria along with a literature review on the topic. The cases involve patients with atypical causes of polyuria: chronic tubulointerstitial nephritis and primary psychogenic polydipsia. A detailed diagnostic process is outlined, and different treatment approaches are discussed. The literature review includes an algorithm for polyuria diagnosis and a discussion of the pathophysiology of diabetes insipidus (both central and nephrogenic) and primary polydipsia, which are common causes of polyuria and should be ruled out as a priority.

The limited body of scientific literature on the differential diagnosis of polyuria underscores the need for clear diagnostic algorithms. The clinical cases and literature review presented here aim to deepen the understanding of the complexity involved in the diagnostic process and emphasize the importance of an individualized approach for each patient with polyuria.