Most people who get COVID-19 recover within a few weeks. But some people—even those who had mild versions of the disease—have symptoms that last weeks or months after an initial COVID infection. These ongoing health problems, called post-COVID conditions (PCC), post-COVID-19 syndrome, long COVID-19, and post-acute sequelae of SARS COV-2 infection (PASC), can decrease quality of life for patients and increase the burden of disease on health systems. As more patients suffer from long COVID, it’s increasingly important to define the symptoms associated with long COVID for effective diagnosis and treatment of the disease.