Long coronavirus disease 2019 (COVID-19) is a multisystem disorder with variable manifestations and duration. One in 10 people with a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection will develop some manifestation of long COVID-19. Currently, there is no one single etiologic factor for the symptoms and signs of long COVID-19 beyond exposure to the SARS-CoV-2 virus. There are multiple theories about the pathophysiology ranging from viral persistence, reactivation, autoimmunity, and immune depletion. Certain risk factors have been identified including female sex, severe acute/hospitalized COVID-19, previous infections with SARS-CoV-2, and absence of vaccinations.