Dr. Mitch Katz rides his bike to work, defying the commuting norm in Los Angeles. Michael Wilson/L.A.County Health Services Dept. hide caption

itoggle caption Michael Wilson/L.A.County Health Services Dept.

Doctors, don't order that CT scan when a less-expensive ultrasound would work just as well, the Choosing Wisely campaign advises. Catherine Yeulet/iStockphoto.com hide caption

itoggle caption Catherine Yeulet/iStockphoto.com

Connor Perruccello-McClellan, a senior at Providence Country Day School in Rhode Island, has been vaccinated against HPV, something less than 1 percent of U.S. males can say. Richard Knox/NPR hide caption

itoggle caption Richard Knox/NPR

Dolphin bite? There's a medical code for that. Simone Di Tonno - Annachiara Fig/iStockphoto.com hide caption

itoggle caption Simone Di Tonno - Annachiara Fig/iStockphoto.com