According to feminine lore, guys simply don't handle pain well. The tiniest twinge of discomfort is enough to reduce most men into helpless, whimpering heaps. Women, on the other hand, can handle the tough stuff. In fact, you can ratchet up the old pain-o-meter to agony and beyond and most women will soldier on without flinching.
The trouble with that theory is -- it's wrong. And now men have the science to prove it.
"The laboratory research seems to indicate that for many kinds -- but not all kinds -- of stimuli, women have a lower tolerance for pain," says Linda LeResche, ScD, a professor of oral medicine at the University of Washington, in Seattle.
But what exactly that means is a puzzle LeResche and other pain researchers across the country are trying to work through. The fact is, no one really knows for sure if women and men perceive pain differently, let alone how they react to it.
Untangling the Mystery of Pain
"There are [so many] overlays of societal and cultural norms and other factors that go into the reporting of pain that it may not have a biological basis at all," says Robert Gear, an assistant professor of oral and maxillofacial surgery at the University of California, in San Francisco. "It certainly could have a biological basis, but there is no way to test it so far."
Researchers have been trying for decades to untangle the mystery of pain. An important breakthrough came in the mid-1960s when scientists discovered that the brain could change or modulate the nervous system in response to pain. Until then it was believed the nerve-brain-pain connection was fixed and inflexible.
"There is some experimental research that suggests the pain modulation systems between men and women may be different," LeResche says. "Females may also have an additional system that uses estrogen."
The 1990s were a fertile time in pain research. What we now know is that pain begins when nociceptors -- small, thin fibers located throughout the body in peripheral nerves -- register trauma to nearby tissue. During surgery, for instance, nociceptors fire as soon as the initial incision is made. They release a bath of chemicals that induces the nerves to carry the pain message to the brain. The chemicals collect in a part of the spinal cord called the dorsal horn and are released to the brain -- where pain is registered.
Even with general anesthesia, a patient's central nervous system remains alert and ushers pain messages back and forth from the nociceptor, through the nerves, into the spinal cord, and on to the brain. The brain responds by washing the spinal cord with glutamate, a chemical that rewires the central nervous system and creates a physical memory of pain.