Photo: George Burns/Harpo Studios

Dr. Oz asks the audience if they look inside the tissue after they blow their nose. Seventy-four percent of audience members say they can't help sneaking a peek. "They're smart," Dr. Oz says. "They're auditing what's going on in their body." 

Dr. Oz says your snot can indicate whether you're getting sick. "If it's green, maybe you should call someone like a doctor."