A leading cause of the bone-loss disease osteoporosis is hyperparathyroidism. Doctors commonly treat this using a class of prescription drugs called bisphosphonates, which are supposed to strengthen bones. A new study found those drugs actually increase the risk of fracture, meaning that taking them is worse than doing nothing at all. The research also revealed that patients who have surgery to remove the overactive parathyroid glands have fewer subsequent bone fractures.