Polyuria–polydipsia syndrome can be caused by central diabetes insipidus, nephrogenic diabetes insipidus or primary polydipsia. To avoid confusion with diabetes mellitus, the name ‘central diabetes insipidus’ was changed in 2022 to arginine vasopressin (AVP) deficiency and ‘nephrogenic diabetes insipidus’ was renamed as AVP resistance. To differentiate the three entities, various osmotic and non-osmotic copeptin-based stimulation tests have been introduced in the past decade. The hypertonic saline test plus plasma copeptin measurement emerged as the test with highest diagnostic accuracy, replacing the water deprivation test as the gold standard in differential diagnosis of the polyuria–polydipsia syndrome. The mainstay of treatment for AVP deficiency is AVP replacement with desmopressin, a synthetic analogue of AVP specific for AVP receptor 2 (AVPR2), which usually leads to rapid improvements in polyuria and polydipsia. The main adverse effect of desmopressin is dilutional hyponatraemia, which can be reduced by regularly performing the so-called desmopressin escape method. Evidence from the past few years suggests an additional oxytocin deficiency in patients with AVP deficiency. This potential deficiency should be further evaluated in future studies, including feasible provocation tests for clinical practice and interventional trials with oxytocin substitution.

多尿多饮综合征可由中枢性尿崩症、肾性尿崩症或原发性多饮引起。为了避免与糖尿病混淆，“中枢性尿崩症”这一名称于 2022 年更改为精氨酸加压素 (AVP) 缺乏症，“肾性尿崩症”更名为 AVP 抵抗。为了区分这三种实体，在过去十年中引入了各种基于和肽素的渗透性和非渗透性刺激测试。高渗盐水试验加血浆和肽素测定成为诊断准确率最高的试验，取代禁水试验成为鉴别诊断多尿多饮综合征的金标准。 AVP 缺乏症的主要治疗方法是用去氨加压素替代 AVP，去氨加压素是 AVP 受体 2 (AVPR2) 特异性的 AVP 合成类似物，通常会导致多尿和烦渴的快速改善。去氨加压素的主要不良反应是稀释性低钠血症，可以通过定期进行所谓的去氨加压素逃逸法来减少。过去几年的证据表明，AVP 缺乏症患者还存在催产素缺乏症。这种潜在的缺陷应在未来的研究中进一步评估，包括临床实践中可行的激发试验和催产素替代的介入试验。