Purpose <p>Aerophagia is a functional gastrointestinal disorder including swallowing air, repeated belching, and disturbing symptoms of air retention in the gastrointestinal tract. Aerophagia can also occur during continuous positive airway pressure (CPAP) therapy. Pressurized air can leak into the stomach causing belching, abdominal distention, discomfort, and flatulence, among other symptoms. There are few studies on CPAP-related aerophagia (C-aerophagia), and the reported prevalence ranges from 8.28 to 16% Our aim was to evaluate aerophagia-related symptoms before and with CPAP therapy.</p> Methods <p>A total of 2004 patients began CPAP therapy at the Helsinki Sleep Apnea policlinic during 2015–2019. A randomly selected sample of 1059 patients were sent a questionnaire to assess symptoms possibly related to aerophagia. Symptom severity was evaluated with a Visual Analogue Scale (VAS).</p> Results <p>We received 324 responses. The most disturbing symptom was flatulence, with VAS increasing from a median of 24 before CPAP to 34 during CPAP (<i>p</i> ≤ 0.001). Dry mouth increased from 16 to 31 (<i>p</i> ≤ 0.001), heartburn decreased from 12 to 10 (<i>p</i> ≤ 0.001), and belching decreased from 12 to 9 (<i>p</i> = 0.018). A total of 29 patients abandoned CPAP therapy. Symptoms of aerophagia were the main cause of abandoning CPAP for 3 patients.</p> Conclusions <p>Most patients who reported symptoms of aerophagia with CPAP therapy were already symptomatic before CPAP initiation. Only flatulence and dry mouth increased slightly with CPAP. Although changes in symptoms were very mild overall, in rare cases (1%) symptoms can be very disturbing and even lead to abandoning CPAP therapy. For clinical practice, it is important to assess whether symptoms of aerophagia are actually related to and worsened by CPAP therapy to avoid unnecessary interventions.</p>