MedlinePlus This link opens in a new windowMedlinePlus is the National Institutes of Health's Web site for patients and their families and friends. Produced by the National Library of Medicine, the world’s largest medical library, it brings you information about diseases, conditions, and wellness issues in language you can understand. MedlinePlus offers reliable, up-to-date health information, anytime, anywhere, for free. Also available in Spanish, with 48 additional languages represented. Includes medical images and videos, interactive tutorials, and a medical encyclopedia.