Think of human relationships as entanglements. How do they bind you; how do they reveal who you really are? Daniel Horowitz for NPR hide caption

itoggle caption Daniel Horowitz for NPR

Harvard University student Elana Simon introduces President Obama before he spoke at the White House Friday about an initiative to encourage research into more precise medicine. Mandel Ngan/AFP/Getty Images hide caption

itoggle caption Mandel Ngan/AFP/Getty Images

Ideally, we'd all eat super healthful diets. But that's not the world we live in, and multivitamins may help bridge the nutritional gaps. Jasper White/Getty Images hide caption

itoggle caption Jasper White/Getty Images

Rhett Krawitt, 6, outside his school in Tiburon, Calif. Seven percent of the children in his school are not vaccinated. Courtesy of Carl Krawitt hide caption

itoggle caption Courtesy of Carl Krawitt

A marijuana bud displayed in Denver. Don't legalize pot, the pediatricians say, but don't lock teenagers up for using it, either. Seth McConnell/The Denver Post/Getty Images hide caption

itoggle caption Seth McConnell/The Denver Post/Getty Images

High school athlete Graham Hill, number 50, suffered a concussion in 2013 while playing football at Trinity Christian Academy in Addison, Texas. Courtesy of Jeffrey McWhorter hide caption

itoggle caption Courtesy of Jeffrey McWhorter

Ultrasound is often used for prenatal screening. It's just one of several prenatal screenings available to pregnant women. iStockphoto hide caption

itoggle caption iStockphoto

The UASK app helps sexually assaulted college students in D.C. access a range of services, from rides to the hospital to phone numbers for counselors. The information is personalized to their school. Another version of the app, ASK, provides the same resources to non-students. Emily Jan/NPR hide caption

itoggle caption Emily Jan/NPR