Disclosed are catheter systems and methods of using the catheter system to acquire mucosal impedance data of a patient. Also disclosed are methods of classifying or otherwise identifying esophageal conditions in a subject based on mucosal impedance data acquired using a catheter system. Unlike conventions systems that require subjective input from a physician to render a diagnosis, the systems and methods described herein can utilize the mucosal impedance measurements to generate a probability that the subject's esophagus corresponds to an esophageal condition or a set of esophageal conditions. In one embodiment, a classification model is used to generate the probability. The classification model may generate the probability based at least in part on a change in the mucosal impedance measurements between a distal location and a proximal location on the subject's esophagus.