Despite great advances in medicine, we still have no idea how to measure a patient’s pain—which has severe consequences for women. Why is ‘pain’ so difficult to diagnose and treat?
Editor’s note: Our readers often ask us to do a deep dive into a topic of interest to them. This Big Story was ‘commissioned’ by subscriber Tresa Fernandez. If you have a request, be sure to write to us at talktous@splainer.in.
Researched by: Rachel John & Anannya Parekh
How do we define pain?
“How much does it hurt?”—that’s the routine question asked by doctors around the world. But how does the medical community define “hurting”?
Defining pain: In 2020, the International Association for the Study of Pain issued a revised definition of pain: “An unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage.” And it added the following context:
- Pain is always a personal experience that is influenced to varying degrees by biological, psychological, and social factors.
- Pain and nociception (how the brain senses threatening sensations) are different phenomena. Pain cannot be inferred solely from activity in sensory neurons.
- Through their life experiences, individuals learn the concept of pain.
- A person’s report of an experience of pain should be respected.
- Although pain usually serves an adaptive role, it may have adverse effects on function and social and psychological well-being.
- Verbal description is only one of several behaviours to express pain; inability to communicate does not negate the possibility that a human or a nonhuman animal experiences pain.
However, adding this context does very little to solve the thorny problem of measuring pain—especially since we now know it can be highly subjective:
For such a universal experience, pain remains much of a mystery – especially the task of determining how much pain someone is in. "We understand it so poorly," says [Stanford researcher] Emma Pierson... "In particular, the fact that human doctors are frequently left flummoxed by why a patient is in pain suggests that our current medical understanding of pain is quite bad."
How do we measure pain?
It is frustratingly subjective and complicated—because there are two people who determine the answer: The doctor and the patient.
McGill Pain Questionnaire: For decades, doctors listened to a person’s description of their pain—“It’s like I’ve been attacked with a stapler”—and used their judgement to prescribe treatment. In the 1970s, two Canadian scientists tried to establish some method to this guesswork with the McGill Pain Questionnaire—which is still used as the primary tool to assess pain.
They sorted words commonly used by patients to describe pain into three categories:
[S]ensory (which included heat, pressure, “throbbing” or “pounding” sensations), affective (which related to emotional effects, such as “tiring”, “sickening”, “gruelling” or “frightful”) and lastly evaluative (evocative of an experience – from “annoying” and “troublesome” to “horrible”, “unbearable” and “excruciating”).
Then they created a grid that spit out an answer—in numbers.
How it works: The patient has to say whether each “descriptor” describes their pain—and, if so, to rate the intensity of the feeling. The doctor checks all the relevant boxes—which gives them a number, or a percentage figure. They use this to assess whether a treatment is working—or not.
Pain Control’s Pain Quality Assessment Scale: In this more recent version, the patient is asked to rate—on a scale of one to ten—how “intense” or “sharp”, “hot” or “cold”, “sensitive”, “tender”, “itchy”, etc—their pain has been over the past week. The problem is that ten is defined as “the most intense pain sensation imaginable.” Well, people’s imaginations can vary based on life experience:
The trouble with this approach is the imprecision of that scale of 1 to 10, where a 10 would be. How does a patient imagine the worst pain ever and give their own pain a number? Middle-class British men who have never been in a war zone may find it hard to imagine anything more agonising than toothache or a tennis injury. Women who have experienced childbirth may, after that experience, rate everything else as a mild 3 or 4.
Biomarkers of pain: In recent years, there has been increasing criticism of relying solely on self-reporting. Scientists are instead mapping the brain to identify an objective "readout" to measure pain:
These technologies rely on finding "biomarkers" for pain – measurable biological variables that correlate with the experience of pain."Without biomarkers we will not be able to properly diagnose – and adequately treat – pain," says Saab. "We will not be able to predict the likelihood of someone with acute back injury to transition to chronic treatment-resistant pain, and we will not be able to objectively monitor response to novel therapies in clinical trials."
One such study uses gamma waves in the brain to measure pain—while others use theta waves. Researchers in Indiana are working on a blood test that will identify the genes involved in pain.
Why is it so hard to measure pain?
In recent decades, our understanding of pain has deepened—but it has not become any easier to measure. That’s why many doctors are increasingly trying ‘out of the box’ treatments.
One: Objective pain is not the same as the experience of pain:
There is growing evidence that brain response to pain doesn’t always have a meaningful relationship to the level of pain a person is experiencing – heightened brain activity doesn’t always mean heightened pain. Contextual factors, study methodology and biological differences between people can all affect brain activity.
Simply put, a brain scan or blood test can’t tell the doctor how much pain you feel.
Two: Pain isn’t just about what your physical self experiences:
Pain is not unidimensional. It doesn’t just come with scale—a lot or a little—it comes with other baggage: how threatening it is, how emotionally disturbing, how it affects your ability to concentrate. The measuring obsession probably comes from the regulators who think that, to understand drugs, you have to show efficacy.
The new approach: A pain research lab in Stanford is working on a holistic approach:
A remarkable feature of the assessment process is that patients are also given scores for psychological states: a scale measures their level of depression, anxiety, anger, physical functioning, pain behaviour and how much pain interferes with their lives. This should allow physicians to use the information to target specific treatments.
It is also experimenting with integrating alternative treatment like mindfulness, behavioural therapy and even acupuncture.
Three: Chronic pain is very different—and comes with its own set of complications. For example, neural scan results for people with chronic conditions may be very different—because long-term exposure to pain may have changed their brain structure and response. Also: these patients build up resistance to drugs and treatments over time. So the treatment has to be very different, as well.
The new approach: “Neuromodulation”—which involves distracting your unhappy brain from brooding on the continual pain signals. The method of choice: “a cunningly deployed electric shock”:
We try to send small bolts of electricity to the spinal cord by inserting a wire in the epidural area. It’s only one or two volts, so the patient feels just a tingling sensation over where the pain is, instead of feeling the actual pain. The patient feels nothing except his pain going down. It’s not invasive—we usually send patients home the same day.
Why self-reporting still matters… a lot!
Because the pain of women and minorities is minimised—and often ignored. If the pain experienced by a patient is subjective—then so is the doctor’s diagnosis—which is shaped by prejudice and dangerous stereotypes.
A gendered history of pain: The persistent refusal to acknowledge women’s pain is summed up in the ‘Yentl syndrome’:
Yentl syndrome’ is named after the heroine of the nineteenth-century short story Yentl the Yeshiva Boy by Isaac Bashevis Singer, who had to disguise herself as a man to study the Talmud. This term has made its way into medical research to suggest that women are only treated seriously if they are perceived to be as sick as a man - or pretend to be one.
That’s because women have been labelled as “hysterical”—thank you, Dr Freud–and prone to being over-emotional or over-sensitive.
The hysterical woman: The psychiatric establishment has removed the word ‘hysteria’—which comes from the Greek word for uterus—from its official manual. But it remains a powerful stereotype in pain management. Women’s pain is often attributed to psychosomatic causes—the official version of ‘you’re imagining it’. Men, OTOH, are viewed as tough—and likely to underplay their pain.
This results in a vast divide in how their self-reported pain is treated:
A review of 77 separate research studies revealed that terms like "sensitive" and "complaining" are more often applied to women's reports of pain. One study of 981 people found that women who came to emergency care due to pain were less likely to receive any pain relief at all, and they had to wait 33% longer than men to be treated. In addition, when men and women reported similar levels of pain, men were given stronger medication to treat it.
Irony alert: Doctors are just as likely to believe women “have a greater capacity to cope with pain because of the pain that accompanies menstruation and childbirth.” So their pain is viewed as ‘natural’ and ‘normal’.
The fall-out: That kind of double standard can be life-or-death for women:
In May 2018 in France, a 22-year old woman called emergency services saying her abdominal pain was so acute she felt she was "going to die." "You'll definitely die one day, like everyone else," the operator replied. When the woman was taken to hospital after a five-hour wait, she had a stroke and died of multiple organ failure.
But more routinely, it means women who report pain in their abdomen are immediately treated for gynaecological conditions. They are more likely to receive anti-anxiety medications than men—instead of painkillers.
Point to note: This is even worse when the condition is chronic—and specific to women:
For instance, researchers who interviewed endometriosis sufferers on their experiences with healthcare practitioners found many struggled to get the support they needed. As one participant put it, “you need to try so hard that they believe you, because they don’t. You experience that immediately, that they don’t believe you.”
But, but, but: There are very real gender differences in how we experience biological pain—because our bodies are built very differently. But we don’t know much about them—because clinical trials until the 1990s were dominated by male participants. And those skewed results still form the basis of pain management today:
That led to a massive body of medical evidence, including pain-focused lab studies, with a predominantly male perspective. “When the history of an ailment, including the defining of textbook cases, is largely being written by men about men, it becomes the precedent to which anyone else is held up,” [Author Abby] Norman says.
Point to note: Everything that holds true for women is far worse for minorities—especially women of colour.
The bottomline: There will never be a one-size-fits-all treatment for pain. Its treatment must always put the patient first. A person’s testimony of their suffering should count far more than the biases of their doctor. We leave you with this nugget that shows how messed up this entire system is:
Many women also have more severe side-effects than men to routine painkillers. Since clinical trials are focused on men, these come out only after the drugs are prescribed. Therefore, doctors just end up taking the less aggressive route rather than just giving them pain meds.
Reading list
BBC News has a number of good pieces on finding an objective pain measure, gender divide in treatment and problems of measuring pain. This Conversation piece has the most data on that divide—Chatelaine has more on medical gaslighting. The Atlantic has a personal account of waiting in an Emergency Room as a woman. Northwell looks at how we can make pain management less gendered.
