Changes in health care are a fundamental part of social and intellectual evolution. The modern practice of scientific medicine depends on the existence of the written and printed word to store medical information. Because computers can transform information as well as store it, new digital tools cannot only record clinical data, they can also generate medical knowledge. In doing so, they make it possible to develop "digital medicine" that is potentially more precise, more effective, more experimental, more widely distributed, and more egalitarian than current medical practice. Critical steps in the creation of digital medicine are careful analysis of the impact of new technologies and coordinated efforts to direct technological development towards creating a new paradigm of medical care.