From the Document: "Long COVID [coronavirus disease], according to the Centers for Disease Control and Prevention (CDC), is the occurrence of new, returning, or ongoing health problems 4 or more weeks after an initial infection with SARS-CoV-2 [severe acute respiratory syndrome coronavirus 2], the virus that causes COVID-19. It is also known by other names, including post-acute COVID, post-COVID conditions, and chronic COVID. Symptoms of long COVID vary from person to person. They may include fatigue, cognitive impairment (or 'brain fog'), muscle or joint pain, shortness of breath, heart palpitations, sleep difficulties, and mood changes. Long COVID can affect multiple organ systems and cause tissue damage. [...] Long COVID is a post-viral syndrome. Post-viral syndromes are well documented for a range of infections. For example, one study found that more than 27 percent of survivors from another coronavirus, severe acute respiratory syndrome (SARS), had chronic fatigue syndrome 4 years after their initial infection. [...] Long COVID has potentially affected up to 23 million Americans, pushing an estimated 1 million people out of work. The full magnitude of health and economic effects is unknown but is expected to be significant. The causes of long COVID are not fully understood, complicating diagnosis and treatment. The condition raises policy questions, such as how best to support patients."
Government Accountability Office: http://www.gao.gov/