Women feel pain more intensely than men, according to a new study of 11,000 men and women who were patients at the Stanford Hospital and Clinics.
Researchers analyzed electronic medical records of patients’ reports of pain across a range of different diseases, and found a distinct gender-driven difference in how much discomfort patients say they felt. The study included 47 disorders — from cancer to back conditions and infectious diseases — and more than 161,000 patient-reported pain scores. The patients were all asked by nurses or other health personnel to rate their pain on an 11-point scale, with 0 representing “no pain” and 11 signifying the “worst pain imaginable.”
Not surprisingly, most responses clustered around either the two extremes of very little pain or extreme pain or the middle score of 5. But overall, women were more likely to indicate higher pain levels than men, says lead author Dr. Atul Butte, chief of systems medicine in the department of pediatrics at Stanford University School of Medicine. And that was true across almost all of the different diseases. “That was the most surprising finding,” says Butte. “We completely wouldn’t have expected such a difference across almost all disorders, where women were reporting a whole pain point higher on the 0-to-10 scale than men.”
Of course, self-reports can’t account for the fact that people may define tolerable and intolerable pain in vastly different ways, says Butte, but the fact that a gender difference emerged from such a large number of patients suggests that the effect is real.
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What accounts for the gender gap? Hormones may explain some of the difference — studies have shown that estrogen in women can help dampen the activity of pain receptors, helping them to tolerate higher levels of pain. That means, however, that they may become more sensitive to pain during low-estrogen parts of the menstrual cycle.
There may also be explanations that have nothing to do with biology. Men, for example, may feel compelled by cultural stereotypes to be tough, and therefore report feeling less pain than they really do —especially when asked by the mostly female nursing staff.
Still, even if non-biological factors are influencing how much pain men and women report, Butte says the difference is worth noting. “The reasons may be biological or they may not be, but we should still be aware of the bias that patients have in reporting pain,” he says. He is hoping to continue the research by following up these results with surveys of patients’ ratings after they were treated for pain. That may help doctors to better address the real pain patients may be feeling.