Millions of people continue to suffer from exhaustion, cognitive problems and other long-lasting symptoms after a coronavirus infection. The exact causes of the illness, known as long Covid, are not known. But new research offers clues, describing the toll the illness takes on the body and why it can be so debilitating.
Patients with severe Covid may wind up in hospitals or on ventilators until their symptoms resolve. Damage to the body from severe Covid — pneumonia, low oxygen, inflammation — typically shows up on traditional diagnostic tests.
Long Covid is different: A chronic illness with a wide variety of symptoms, many of which are not explainable using conventional lab tests. Difficulties in detecting the illness have led some doctors to dismiss patients, or to misdiagnose their symptoms as psychosomatic. But researchers looking more deeply at long Covid patients have found a wide range of visible dysfunction throughout the body.
Studies estimate that perhaps 10 to 30 percent of people infected with the coronavirus may develop long-term symptoms. It’s unclear why some people develop long Covid and others don’t, but four factors appear to increase the risk: high levels of viral RNA early during an infection, the presence of certain autoantibodies, the reactivation of Epstein-Barr virus and having Type 2 diabetes.