Inclusion Criteria:  Being at least 18 years or older Approval given both written and orally to the study participation COVID-19 positivity proven by reverse transcription-polymerase chain reaction (RT-PCR) testing At least one evaluation/consultation performed by a pulmonary medicine specialist OR admission to pulmonary medicine ward from another department in the hospital First hospital admission has to be via emergency ward, regardless of the concurrent hospital stay. Cooperation at an acceptable degree for pulmonary function testing.  Exclusion Criteria:  Any contraindication presence for pulmonary function testing (such as anatomic abnormalities, recent cardiac history, and severe respiratory failure) Former COVID-19 history. Persistent pulmonary or other systemic pathology (which prevents hospital discharge) Refusal to participate in the monthly evaluation. Persistent COVID-19 RT-PCR presence (which prevents PFT testing) Known severe limitation in former PFT testing (FEV1 being lower than 30%)