[COVID-19 and post-COVID - Jekyll and Hyde of modern medicine].

COVID-19 pandemic has massive impact on the whole world, lead to the death of milions of people and required excessive restrictions with large economical, psychological and other impacts. Post-COVID syndrome is defined according to the Czech pneumological and phtizeological society as a complex of symptoms persisting for more than 12 weeks from the acute stage of COVID-19 and which is not possible to explain by other causes. Exact pathopysiological mechanisms and its frequency are still not known, and the data from the literature are not consisent.