New research shows which of those patients are at the highest risk for developing serious complications. Overall, three medical conditions significantly increased the risk of death: obesity, hypertension and diabetes. In particular, morbid obesity and hypertension more than doubled the risk of death, and the effect was additive. Essentially, having any of these three conditions raised a person’s risk from that of a young person to a middle-aged person. The same study found that 10% of young adults sick enough to be hospitalized with COVID-19 required a ventilator.