Weakened and frightened by illness, patients face an awesome barrage of medical information, technology, traditions, and jargon. Yet there is no other time when it is more important for them to participate in decisions about their medical care. No matter how expert or empathic the physician, it is the patient who endures or enjoys the outcomes of medical choices: the discomfort of diagnostic procedures, the disfigurement of surgery, the complications of drug therapy, and the joy of seemingly miraculous cures. We have come a long way from the paternalism in medicine that excluded patients from discussions about their own health. . . .