Take a night flight into the restless world of sleep apnea. You’ll see what sleep apnea looks like as a sleeper repeatedly stops breathing, gasps for breath, and awakens just enough to start breathing again. View, from the inside, how collapsed tissues block off breathing. Fly down into the myriad branches of the airways. Dr. Katherine Sharkey of Brown University and Dr. Cynthia Geyer of Canyon Ranch explain airway blockage and why it’s usually due to anatomical features, such as an enlarged neck. You’ll see the regions of the brain affected by sleep apnea. Obesity can cause sleep apnea, but evidence points to a reverse relationship as well: sleep apnea disrupts hormones, increases hunger, and raises insulin and glucose levels—leading to diabetes. Get close-up looks at other organs affected by sleep apnea: the blood vessels, heart, and lungs. You’ll see polysomnography—overnight sleep monitoring—in action. Successful treatment gives the sleep apnea sufferer a new lease on life.