Women report more intense, more numerous, and more frequent bodily symptoms than men. This difference appears in samples of medical patients and in community samples, whether or not gynecologic and reproductive symptoms are excluded, and whether all bodily symptoms or only those which are medically unexplained are examined. More limited, but suggestive, literature on experimental pain, symptom reporting in childhood, and pain thresholds in animals are compatible with these findings in adults. A number of contributory factors have been implicated, supported by varying degrees of evidence. These include innate differences in somatic and visceral perception; differences in symptom labeling, description, and reporting; the socialization process, which leads to differences in the readiness to acknowledge and disclose discomfort; a sex differential in the incidence of abuse and violence; sex differences in the prevalence of anxiety and depressive disorders; and gender bias in research and in clinical practice. General internists need to keep these factors in mind in obtaining the clinical history, understanding the meaning and significance that symptoms hold for each patient, and providing symptom relief.