Perhaps one of the most confusing (and terrifying) things about COVID-19 is how suddenly the illness goes from mild to severe. While researchers are still studying and learning new things about the novel coronavirus virus every day, they still haven’t pieced together why, exactly, some people get so sick while others present no symptoms at all.

In the case of COVID-19, it’s a completely new illness that your body hasn’t detected before, explains Reynold Panettieri, M.D., a lung specialist and vice chancellor for translational medicine and science at Rutgers University. Essentially, your body may not know how to handle the presence of the virus and overreact. To read the full story.