Kristen Miller talks over the risks and benefits of colonoscopy with Stephen Hanauer, chief of gastroenterology at the University of Chicago Medical Center. Brian Kersey/AP hide caption

itoggle caption Brian Kersey/AP

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

A package of K2, a concoction of dried herbs sprayed with chemicals sometimes called synthetic marijuana. New York moved to ban a wide range of products like these this week. Kelley McCall/AP hide caption

itoggle caption Kelley McCall/AP

Chhay Meth, 9, suffering through an attack of malaria at the family's home in O'treng village on the outskirts of Pailin, Cambodia, in 2009. A drug-resistant form of malaria in the region medical led officials to declare a health emergency. David Longstreath/AP hide caption

itoggle caption David Longstreath/AP

An artist on Rio de Janeiro's Copacabana beach puts the final touches on a sand sculpture of the assassin bug, which spreads Chagas disease. The sculpture was part of an event in 2009 commemorating the 100th anniversary of the discovery of the disease. Vanderlei Almeida/AFP/Getty Images hide caption

itoggle caption Vanderlei Almeida/AFP/Getty Images