The relationship of sex and clinical pain to experimental pain responses

Considerable research indicates increased experience of clinical pain among females relative to males, and females also demonstrate enhanced responses to experimentally-induced pain. However, previous research has not investigated the relationship between clinical and experimental pain responses in healthy females and males. This experiment examined recent clinical pain as well as thermal pain thresholds and tolerances in 209 (117 female, 92 male) healthy young adults. All subjects completed questionnaires concerning pain-related symptoms over the previous month and subsequently underwent thermal pain assessment. Females reported a larger number of pain sites and greater health care utilization over the month preceding the experimental session, and females also exhibited greater sensitivity to thermal stimuli. In addition, females above the median on the number of pain episodes demonstrated greater thermal pain sensitivity compared to females below the median, but thermal pain responses did not differ as a function of clinical pain among males. The differences remained significant after correcting for psychological variables including hypervigilance and sex role expectancies. These results indicate that experimental pain responses may be more clinically relevant for females than males. Potential explanations and implications for this pattern of results are discussed.