Objective <p>The primary hyperventilation syndrome (HVS) is characterized by somatic/psychological symptoms, which may be related to abnormalities of ventilatory control, accompanied by sustained hypocapnia and respiratory alkalosis. The purpose of this study is to compare primary HVS with HVS secondary to respiratory infections.</p> Method <p>A total of 167 patients diagnosed with HVS from January 1st, 2024, to May 31st, 2025, were included in this research. Participants were grouped according to positive or negative respiratory infection status. Demographic characteristics, laboratory examinations, and clinical outcomes were retrospectively collected and compared between the two groups.</p> Results <p>In total, seventy-six HVS patients were secondary to respiratory infections, while the remaining 91 patients were primary. Primary HVS patients were mainly induced by psychological factors, since 85% felt tense or anxious before. There was a significantly higher Nijmegen Questionnaire score in patients with HVS secondary to respiratory infections. Besides, this group presented a significantly lower level of electrolytes, as well as a higher level of inflammatory condition on admission. The six-month recurrence rate also showed significantly higher for those in the secondary group.</p> Conclusion <p>HVS patients secondary to respiratory infections presented more severe hyperventilation syndromes and worse clinical outcomes. Appropriate managements specific to infection prevention, as well as respiratory training methods, could be provided to impede the recurrence of hyperventilation syndrome.</p> Clinical trial number <p>Not applicable.</p>