New evidence shows that patients with Long COVID syndrome continue to have higher measures of blood clotting, which may help explain their persistent symptoms, such as reduced physical fitness and fatigue.

The study, led by researchers from RCSI University of Medicine and Health Sciences, is published in the Journal of Thrombosis and Haemostasis.

Previous work by the same group studied the dangerous clotting observed in patients with severe acute COVID-19. However, far less is known about Long COVID syndrome, where symptoms can last weeks to months after the initial infection has resolved and is estimated to affect millions of people worldwide.