For a long time people have kept emotions out of the deliberate tools of medicine and science; scientists, physicians, and patients have often felt and sometimes expressed emotion, but no tools could sense, measure, and respond to their affective information. A series of recent studies indicates that emotions, particularly stress, anger, and depression, are important factors with serious and significant implications for health. This paper highlights research at the MIT Media Lab aimed at giving computers the ability to comfortably sense, recognize, and respond to certain aspects of human emotion, especially affective states such as frustration, confusion, interest, stress, anger, and joy. Examples of recently developed systems are shown, including computer systems that are wearable and computers that respond to people with a kind of active listening, empathy, and sympathy. Results are reported for computer recognition of emotion, for teaching affective skills to autistics, and for having computers help users manage emotions such as frustration.