Aug. 15, 2001 -- Males and females are hardwired for pain, but the circuitry is different. That internal wiring difference, combined with sociocultural influences and a powerful push from hormones, means that when a man tells a woman that he feels her pain -- he doesn't.
The good news, according to pain researchers, is that someday "a woman who has pain may be able to get relief from a drug designed specifically for pain in women," says Jeffrey Mogil, PhD, a pain researcher at McGill University in Montreal.
And that relief can't come a minute too soon according to results of a 1999 Gallup Survey that found that 46% of American women say they experienced daily pain compared to 37% of men. Seventeen percent of women said they had frequent headaches, 24% backaches, 20% arthritis, and one in four women had sore feet.
"Pain is not what travels along the nerves," says pain researcher Roger B. Fillingim, PhD, of the University of Florida, in Gainesville. "Pain is our own personal experience ... All pain is real," he says, adding that women are two-to-three-times more likely to have migraine headaches than men, and women are six-times more likely to have fibromyalgia.
Fillingim presented new findings on gender differences in pain at a recent conference sponsored by the American Medical Women's Association and the Cleveland Clinic Foundation.
Fillingim tells WebMD that some gender differences can be attributed to hormones. Younger women, for example, "report greater pain sensitivity during the premenstrual period."
R. Norman Harden, MD, medical director of the chronic pain care center at the Rehabilitation Institute of Chicago, says that only one painful condition, migraine headaches, can really be attributed to hormones. During childbearing years, women are six-times more likely to have migraine headaches than men, he says.
Harden says that there are three main factors behind gender differences in pain:
- Hormonal influences, such as what's seen with migraine headaches
- Bodily differences among individual men and women, regarding where their pain-receiving areas are located,
- The different ways in which men and women are raised
Fillingim agrees that society has a significant influence on male and female pain. Women may experience pain based on expectations gleaned from mothers or sisters. For example, a woman may expect more pain from a headache because she observed her mother suffering from painful headaches. "Awareness may heighten a woman's own pain experience," he says.
Fillingim, adds, however, that when it comes to reporting pain, society is more accepting of women doing it than men. He says he tested this societal difference in a laboratory experiment in which the male and female volunteers worked with either very physically attractive investigators or less-attractive investigators of the opposite sex. The male response was dependent on the investigator -- men reported less pain when the investigator was attractive, while women's responses were the same regardless.
Mogil says that while this may be true for humans, "I don't think that the male mice ... are trying to be 'macho' or that the female mice are trying for demure." Mogil says that his animal experiments suggest that the experience of pain is gender-specific in several species.
"And this is what is really exciting," says Mogil. The male-female pain research has already turned up evidence that a class of painkillers called kappa-agonists is actually much more effective among women than among men.
Harden says he expects that there will be other painkillers that will also demonstrate gender-specific properties, but he says that will require more research because "when these drugs were developed, the clinical studies were only done in young men. We have no clinical trial data on women."
Meanwhile, Harden says there is enough scientific information to conclude that women are not more pain tolerant simply because "it is the women who have the babies, so they must be tougher" nor are they "wimps because they complain more about pain." Rather, he says women simply are different than men.