Feb. 18, 2002 -- In the battle of the sexes, there are some real differences among the casualties.
Men and women experience pain differently. Women are more likely to be stricken with painful conditions like migraine headaches, fibromyalgia, knee pain, certain types of spinal pain, and chronic facial pain. But that doesn't always mean these conditions get treatment.
"One in five women lives with chronic pain, but despite that alarming number, their cries for help often go unheard," says Mark Allen Young, MD, a pain management specialist at Johns Hopkins University School of Medicine and author of Women and Pain.
Women, on average, spend much more time describing their pain, and that can lead some doctors not to believe them, Young says. Often, women are dismissed as being too emotional -- a misperception that may lead them to receive inadequate care.
In Pain, Emotion Matters
"There is a perception among some women that their pain is not taken seriously," says Linda LeResche, ScD, a research professor in the department of oral medicine at the University of Washington in Seattle. "But I wouldn't paint all doctors with that same brush," she adds.
If a woman reports pain, and her doctor asks if she's been under stress, she may think the doctor is not taking her seriously -- and that her physical problem is being ignored, says LeResche. "But we get hung up believing that it's either the body or the mind, that there's no connection between the two."
"Pain is processed in the brain," she explains. "It's not all in your head, but it's also not just in the part of your toe that's hurting."
Researchers are only beginning to piece together the puzzle of why men and women process pain differently, but it's already clear that the differences have to do not only with the fact that men and women have different body types, but also that they cope with things like pain in very different ways.
Are Women Pain-Smart?
Karen J. Berkley, PhD, a professor of neuroscience at Florida State University in Tallahassee, says women learn to recognize and deal with pain in a unique way almost from birth: We're all born with reflexes to withdraw from pain, but people need to learn how to take care of that pain, she says, and men and women learn differently.
According to Berkley, pain "represents a recognition that you've got to react to something that's potentially harmful." And it's easy to see, she says, how, almost from birth, boys and girls learn differently what is painful and how to deal with it.
"Females are raised to recognize something as dangerous and to find ways to help ourselves and others," she explains.
According to Young, women in general are better at taking care of themselves and their health: "Women are more likely to talk about their pain, to seek help from friends or doctors. They're not ashamed of their pain," he says.
The fact that women are more likely to perceive pain and to report it at a lower intensity level than men do may explain why women also seek healthcare more often. "Some might say that women are more vulnerable to pain," says Berkley. "Really, they're smarter at dealing with it."
'Cells Know Their Sex'
Hormones may also contribute to the differences between how men and women handle pain.
LeResche has been studying hormones in patients with jaw disorders. Before puberty, she explains, these conditions are rare and occur equally frequently in boys and girls. The rates for both sexes go up after puberty, with women being about twice as likely as men to have these conditions. But after menopause, the rate for women drops down to the same rate as for men.
This is also true of migraine headaches, the condition that seems to show the clearest influence of hormones. Researchers are also studying the possibility that fibromyalgia is influenced by hormones.
In April 2001, a landmark report cosponsored by the Institute of Medicine and the U.S. Department of Health and Human Services recommended that sex differences be taken into account when designing and analyzing studies at all levels of health-related research.
"Our report found that sex matters from the womb to the tomb," says Berkley, who took part in the project. "In other words, throughout one's life, every cell knows its sex."
Reactions to Drugs Differ, Too
Men and women don't just process pain differently: They also respond differently to pain medication. But until recently, most clinical trials lacked vital information about dosage and side effects relevant to women.
For example, research has shown that certain pain-relieving drugs called kappa opiates, such as Stadol, are highly effective in women. They were originally thought to be ineffective, however, because they had been tested only on men.
Recognizing that prescription drugs affect men and women differently, the FDA issued a regulation in 1998 requiring drug companies to include sex-specific information about safety and effectiveness when applying for new drug approval. But by the end of 2000, one-third of drug applications contained no such information.
What's worse, eight of the 10 prescription drugs taken off the market between January 1997 and February 2001 caused more negative effects in women than in men. The following drugs were thought to be responsible and were widely prescribed to both sexes:
- Seldane, an antihistamine.
- Posicor, a cardiovascular drug.
- Hismanol, an antihistamine.
- Propulsid, a gastrointestinal drug.
"There is clearly a need for major pharmaceutical houses and research institutions to design clinical trials that take into account women's unique needs," Young says.