Why Are Women More Likely to Have Chronic Pain? Blame Hormones
/By Crystal Lindell
Chronic pain typically lasts longer for women than men, and new research suggests hormones could be to blame. That’s according to a study at Michigan State University, published in Science Immunology.
We’ve known for some time that women are more likely to have chronic pain, and that is likely because it takes longer for their pain to resolve. Acute pain becomes chronic when it lasts longer than three months.
The researchers looked into the potential causes of this phenomenon, and found that differences in hormone-regulated immune cells, called monocytes, seem to be the culprit.
A subset of monocytes releases a molecule – called interleukin-10 or IL-10 – that can “switch off” pain. Those cells are more active in males because of higher levels of sex hormones such as testosterone. Females, however, experienced longer-lasting pain and delayed recovery because their monocytes were less active.
When the team tested their theory on laboratory mice, they discovered the same pattern they saw in human patients. They performed five different tests on the mice to make sure what they saw wasn’t an anomaly. Each time, the results were the same.
“The difference in pain between men and women has a biological basis,” lead author Geoffroy Laumet, an associate professor of physiology at MSU, explained in a press release. “It’s not in your head, and you’re not soft. It’s in your immune system.
“This study shows that pain resolution is not a passive process. It is an active, immune-driven one.”
These findings could mean those immune cells can be manipulated into producing more signals to calm pain.
Laumet hopes this research could one day help millions of people experience relief with non-opioid treatments — and ensure women’s pain is taken more seriously. Such treatments could help acute pain resolve faster, instead of relying on analgesics to block pain signals.
The next step is to investigate how treatments could target this pathway and boost IL-10 production, although Laument admits that could take years.
“Future researchers can build on this work,” Laumet said. “This opens new avenues for non-opioid therapies aimed at preventing chronic pain before it’s established.”
In the meantime, hopefully this type of research will encourage medical professionals to believe women when they say their pain is not going away.
The MSU study was funded by the National Institutes of Health and the Department of Defense.
