Empathic understanding in practitioner relationships is postulated as necessary for adherence to therapeutic regimens. It is considered to be one of the most important practitioner relationship skills leading ultimately to patient health benefit. Research literature from a wide-range of health disciplines including personality theory, social psychology, psychotherapy, psycho-analysis, and practitioner-patient communication highlights the key role of empathic processes in personal health care. A model of empathic understanding is described which attempts to integrate the substantive findings in the research literature and seeks to generate new ideas for further investigation. The model addresses theoretical relationships between practitioners' empathic understanding, patients' knowledge of their illness and motivation to get better, adherence to treatment advice, and outcome. Recent work on the selection and training of medical and nursing staff in empathic skills is reviewed. A number of areas for future research are outlined including the effect of individual practitioner differences in the components of empathy, empathic compatibility in practitioner-patient dyads, fluctuations in levels of practitioner empathy during long-term care, specific practitioner behaviours which communicate empathy, and the relationship between factors of patient satisfaction and the perception of empathic understanding.