HHS found that 19 percent of nurse aides who'd been disciplined had a prior conviction that would have shown up on a background check. Matt Rourke/AP hide caption

itoggle caption Matt Rourke/AP

More elderly drivers will hit the road in the next decade, but family members wonder: When is it time for elderly loved ones to move to the passenger seat? Martin Novak/iStockphoto.com hide caption

itoggle caption Martin Novak/iStockphoto.com

Sam Berns, 15, who has the very rare premature-aging disease progeria, plays the drums in his high school's marching band. Courtesy of the Progeria Research Foundation hide caption

itoggle caption Courtesy of the Progeria Research Foundation

A rhesus monkey eats watermelon, provided by zookeepers, at the Kamla Nehru Zoological Gardens in India in May 2012. Sam Panthaky/AFP/Getty Images hide caption

itoggle caption Sam Panthaky/AFP/Getty Images

The latest data paint a brighter picture of aging in America. Lisa F. Young/iStockphoto.com hide caption

itoggle caption Lisa F. Young/iStockphoto.com

HIV treatment regimens, like the pills in this patient's hand, keep AIDS at bay, but can take a harsh physical toll over the course of many years. Amy Sancetta/AP hide caption

itoggle caption Amy Sancetta/AP

Bacteroides species are some of the most common bacteria in the human gut. Enviornmental Health Perspectives hide caption

itoggle caption Enviornmental Health Perspectives