Nearly a year into the global coronavirus pandemic, scientists, doctors and patients are beginning to unlock a puzzling phenomenon: For many patients, including young ones who never required hospitalization, Covid-19 has a devastating second act.
Many are dealing with symptoms weeks or months after they were expected to recover, often with puzzling new complications that can affect the entire body—severe fatigue, cognitive issues and memory lapses, digestive problems, erratic heart rates, headaches, dizziness, fluctuating…