Background <p>Hiatal hernia (HH), a common digestive disease, may impact the respiratory system, but systematic evaluation of its effect on cardiopulmonary function and associations with clinical indicators remains insufficient.</p> Methods <p>This retrospective study included 248 HH patients (118 surgical [SHH], 130 non-surgical [NHH]) and 516 healthy controls (HC) from The First Affiliated Hospital of Zhejiang University School of Medicine (January 2021–December 2024).&#xa0;Data on basic information, imaging, pulmonary function, echocardiography, and reflux symptoms were collected. Differences in cardiopulmonary function among groups were compared through multi-factor adjustment analysis, and related influencing factors were explored.</p> Results <p>HH patients had higher pulmonary infection risk, poorer ventilatory/small airway/diffusing function, and wider pulmonary artery (PA) diameter. NHH patients were older, had larger hernia sacs, and worse cardiopulmonary function but fewer reflux symptoms.&#xa0;The differences in cardiopulmonary function among the above groups weakened after excluding confounding factors such as age. Advanced age and large hernia sac (not reflux) correlated with impaired cardiopulmonary function. 81.2% of SHH patients had improved postoperative respiratory symptoms.</p> Conclusion <p>HH is associated with cardiopulmonary dysfunction, manifested by increased risk of pulmonary infection, restrictive ventilatory dysfunction, decreased diffusing capacity, and widened PA diameter. These associations are not significantly associated with reflux and mainly related to age and hernia sac size. This study has limitations due to its retrospective design and can only provide preliminary data reference for exploring the cardiopulmonary function characteristics of HH and their related influencing factors.</p> Graphical Abstract <p></p>