Prediabetes is common in the U.S. — around 1 in 3 people have it. And many people may not know they have it. But last year, the FDA approved the first over-the-counter continuous glucose monitor. Since then, more people without diabetes have started checking their blood glucose levels. Diabetologist and University of California, San Francisco professor of medicine Dr. Sarah Kim shares the science behind blood glucose with host Emily Kwong. Check out more of NPR’s coverage about continuous glucose monitors.Interested in more science of the human body? Email us your question at shortwave@npr.org.Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy