BACKGROUND: Current definitions of pain suggest that emotion is an essential component of pain, however, the presumed relationship between emotion and pain, and the specific emotions that are involved in pain experiences have yet to be clarified.OBJECTIVE: To address these issues in order to assist in making current conceptualizations of pain more explicit.DESIGN: Thirty adult patients undergoing routine blood tests were videotaped. Spontaneous facial reactions were examined for distinct expressions of emotion and pain occurring at baseline, swabbing and venepuncture intervals. Expressions were assessed objectively with the Facial Action Coding System (FACS) and rated subjectively by 48 untrained judges. Patients also provided baseline and postneedle self-reports of experienced pain.RESULTS: Comparison of venepuncture, swabbing and baseline segments revealed that objective measures of pain-related facial activity, subjective ratings of pain expression and self-reported ratings of pain increased significantly from baseline to venepuncture and that measures of disgust, anger, fear and happiness also varied significantly across segments. Regression analyses indicated that measures of pain could be predicted from measures of specific emotions.CONCLUSIONS: Emotion is an essential component of the acute phasic pain experienced during venepuncture. Although the occurrence of specific emotions varied as a function of pain, objective behavioural indexes and subjective behavioural ratings of pain were predicted by different emotional components than patients' self-reports.