Gender Differences in Pain Experience and Pain Management

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Men are from Mars and women are from Venus.

Remember when that relationship self-help book swept the nation and sparked conversations about the many differences in the way men and women experience and behave in relationships?

It’s an open debate as to whether the book offered any valuable or practical relationship advice to men and women. Some loved it, while others panned it.

The book itself was based on years of personal and professional experience by the author, a PhD-level counselor who specialized in couple’s therapy. Which means that while the book drew its primary conclusions from a broad base of evidence collected by a professional therapist, the evidence was neither peer-reviewed nor acquired through techniques established by contemporary scientific methods and practices.

Therefore, it was, essentially, a book-length opinion piece on gender differences in relationship behaviors. Informed opinion, but opinion, nonetheless.

Recently, however, research shows verifiable, evidence-based gender differences in a completely separate area: the way men and women experience pain, and the way that experience affects how doctors should manage pain – particularly chronic pain – in men and women.

The resurgence in research in this area is related to the opioid crisis. Since opioids are the most effective pain relief medication known to medical science, that stands to reason: with misuse and overdose at higher levels and rates than ever before, it’s important for scientists to explore every aspect of opioid treatment possible, so that they may understand more, and, when effective and practical, offer non-opioid treatment for both acute and chronic pain.

The new data is driven by the opioid crisis, but our knowledge of gender differences in pain experience predates the opioid crisis.

Gender Differences in Pain Experience: The Origin of the Current Model

In the year 2000, researcher RB Fillingham published the paper “Sex, Gender, and Pain: Women and Men Really Are Different” which offered evidence that men and women do, in fact, experience pain in different ways. He concluded these gender differences fell into three categories:

  1. Biological. Evidence shows that the relative amounts of the sex hormones estrogen and testosterone circulating in the bloodstream play a role in the subjective experience of pain. Estrogen appeared to be connected to increased sensitivity to pain, while testosterone appeared to be connected to increased tolerance to pain. In addition, variations in endogenous (internal) pain regulation mechanisms contribute to gender differences in experiencing pain.
  2. Psychological. Both anxiety and depression are linked to elevated levels of pain experience. Anxiety appears to increase pain sensitivity in men, but not in women. Research shows that in the general population, depression is associated with chronic pain conditions in both men and women. However, it’s widely accepted that depression is correlated with elevated pain perception and increased chronic pain conditions in women and not men.
  3. Social. Cultural and social gender role expectations affect how men and women report pain and its severity. Data shows that women report more chronic pain than men, and that men underreport intensity and severity of pain because of the social expectation that they should be able to handle pain without reporting it, which would be construed as weakness, which contradicts the “strong man” archetype dominant in our society.

In addition, data supports the idea that women experience pain more intensely and report chronic pain conditions more than men. The CDC reports that roughly 50 million – or around 20.4% – of adults in the U.S. live with chronic pain and that around 20 million – 8.0% – live with high-impact chronic pain. Prevalence of both chronic and high-impact chronic pain is higher in women than in men.

With all that said – women are more sensitive to pain and report more chronic pain than men – we’d like to throw a wrench in the works: more recent studies – as in released in January, 2019 – show that in experiments with rodents and humans, the male experience of pain was directly tied to earlier experiences of pain, and that men (and male rodents) that experienced pain early in life were more reactive to pain later in life and more likely to develop chronic pain conditions later in life.

How Gender Difference Affect Pain Treatment and Management

The data on gender differences in pain is confounding from top to bottom. What we haven’t shared yet are some important data points related to opioids:

  • Women need more opioid medication than men to achieve the same analgesic (pain-relieving) effect.
  • Women are more likely than men to misuse prescription opioids.
  • Women who develop an opioid use disorder are more likely to begin with prescription medication.
  • More men than women are diagnosed with substance use disorders in general, and opioid use disorders in particular.
  • More men die from accidental overdose than women each year – but overdose rates for women have steadily increased from 2014 – present.

That’s what makes a recent article published in Nature: The International Journal of Science so interesting: researchers found distinct differences in the physiological mechanisms by which men and women experience pain, and those differences are directly related to presence – or absence – of the male sex hormone, testosterone.

The levels of pain they studied showed no gender differences – what was different was the pathway by which pain signals were transferred by pain receptors to the brain. In women, the key player in pain signal transmission were T-cells, which are immune cells found in the central nervous system. In men, the key player in pain signal transmission were microglia, which are a completely different type of immune cells, also found in the central nervous system.

Why is this important?

Let’s reread the first three bullet points above. First, women need more opioid medication to achieve the same effect. Second, women are more likely to misuse prescription opioids. Third, women who develop an opioid use disorder are more likely to begin with a prescription medication than men. When combined with the data that shows women are more likely to live with chronic pain disorders and high-impact chronic pain disorders, and that women are more likely to report pain than men, this means that women – since opioids are simultaneously the most effective and most dangerous pain medications we have – are more likely to be prescribed opioids, and at higher doses, than men. Which, in turn, increases their vulnerability to opioid use disorders, and all the negative physical, psychological, and emotional consequences of opioid addiction.

That’s why information on gender differences in the mechanics of pain transmission is crucial to the future of pain experience, pain medication practices, and pain management for women: if this data leads researchers to develop non-opioid analgesics that are as effective as opioids, then doctors will prescribe them. And women – who experience more chronic pain than men – who need them can rest assured they’re on a course of treatment that allows them to manage their pain effectively, without the risk of developing an opioid use disorder.

If that were to happen, it would be a very big deal, indeed – and add another tool to the clinical toolbox to help people live lives free from the devastating cycles of opioid addiction.