Gastro-esophageal reflux disease (GERD) occurs in about 25% of the general population. The complexity of the disease and the multiplicity of its clinical manifestations impair the availability of a singular diagnostic test. The majority of GERD patients do not have any endoscopically visible lesions, the so-called non-erosive reflux disease (NERD). This latter population consists of several subgroups characterized by: 1. excess of acid; 2. normal acid, but hypersensitivity to acid or weakly acidic reflux; 3. normal acid, but lack of any relationship between symptoms and reflux episodes. At present, 24-h impedance-pH monitoring represents the best diagnostic tool to detect abnormal reflux and to correlate symptoms to reflux episodes. Moreover, the recent adoption of novel impedance metrics, such as mean nocturnal baseline impedance and post-reflux swallow-induced peristaltic wave index, seem to be able to improve the diagnostic yield of 24-h impedance-pH monitoring, making this test the most accurate in diagnosis of GERD.

胃食管反流病 (GERD) 发生在大约 25% 的普通人群中。该疾病的复杂性及其临床表现的多样性削弱了单一诊断测试的可用性。大多数 GERD 患者没有任何内窥镜可见的病变，即所谓的非糜烂性反流病 (NERD)。后者由几个亚组组成，其特点是： 1. 过量的酸；2.正常酸，但对酸过敏或弱酸反流；3. 酸度正常，但症状与反流发作之间没有任何关系。目前，24 小时阻抗-pH 监测是检测反流异常并将症状与反流发作相关联的最佳诊断工具。此外，最近采用了新的阻抗度量，