Inclusion Criteria:  Post-COVID-19 Group:  Patients after SARS-CoV-2 infection with signs of Post-COVID-19 ≥18 years written informed consent  Healthy controls:  No history of SARS-CoV-2 infection ≥18 years written informed consent  Exclusion Criteria:  Post-COVID-19 Group:  Diagnosis of a breathing-related sleep disorder before SARS-CoV-2 infection BMI >25kg/m2  Healthy controls:  Diagnosis of a breathing-related sleep disorder BMI >25kg/m2