The fascinating science of pain – and why everyone feels it differently

The Guardian

2 days ago

Some say it was John Sattler's own fault. The lead-up to the 1970 rugby league grand final had been tense; the team he led, the South Sydney Rabbitohs, had lost the 1969 final. Here was an opportunity for redemption. The Rabbitohs were not about to let glory slip through their fingers again.
Soon after the starting whistle, Sattler went in for a tackle. As he untangled – in a move not uncommon in the sport at the time – he gave the Manly Sea Eagles' John Bucknall a clip on the ear.
Seconds later – just three minutes into the game – the towering second rower returned favour with force: Bucknall's mighty right arm bore down on Sattler, breaking his jaw in three places and tearing his skin; he would later need eight stitches. When his teammate Bob McCarthy turned to check on him, he saw his captain spurting blood, his jaw hanging low. Forty years later Sattler would recall that moment. One thought raged in his shattered head: 'I have never felt pain like this in my life.'
But he played on. Tackling heaving muscular players as they advanced. Being tackled in turn, around the head, as he pushed forward. All the while he could feel his jaw in pieces.
At half-time the Rabbitohs were leading. In the locker room, Sattler warned his teammates, 'Don't play me out of this grand final.'
McCarthy told him, 'Mate, you've got to go off.'
He refused. 'I'm staying.'
Sattler played the whole game. The remaining 77 minutes. At the end, he gave a speech and ran a lap of honour. The Rabbitohs had won. The back page of the next day's Sunday Mirror screamed 'BROKEN JAW HERO'.
A photograph of Sattler, his heavy green and red jersey rolled up to the elbows, the neck grubby with blood, his mangled swollen jaw, carried on the shoulders of teammates, has become one of Australian sport's most well-known images. His grand final performance has been hailed as 'the most famous show of playing through pain in Australian sporting history'. Sattler, inextricably linked to the jaw he ultimately had to have wired back together, for decades hence was lauded for his courage, celebrated as one of the toughest men to have played the game.
Because John Sattler could withstand the pain.
How can a person bitten by a shark calmly paddle their surfboard to safety, then later liken the sensation of the predator clamping down on their limb to the feeling of someone giving their arm 'a shake'? How is it that a woman can have a cyst on her ovary burst, her abdomen steadily fill with blood, but continue working at her desk for six hours? Or that a soldier can have his legs blown off then direct his own emergency treatment?
Each one of us feels pain. We all stub our toes, burn our fingers, knock our knees. And worse. The problem with living in just one mind and body is that we can never know whether our six out of 10 on the pain scale is the same as the patient in the chair next to us.
About one in five adults experience chronic pain; it can be debilitating and patients have been historically dismissed, disrespected and under-treated. Acute pain is different; it's short periods of pain usually associated with an injury, illness or tissue damage. Because all humans experience acute injury or illness, we each have a sense of our pain response. Many of us wonder, 'Do I have a high pain threshold?' And we have each at some point been asked – by a doctor, by a nurse, by a teammate – 'What's your pain on a scale of one to 10?'
The ability of some people to experience serious injury without appearing to feel serious pain has been fodder for legend and research for centuries. Withstanding pain has been heralded as heroism or a freakish anomaly.
But what is happening in the body and mind of a person who does not seem to feel the pain they 'should' be feeling. Do we all have the capacity to be one of these heroic freaks?
And how did John Sattler play those 77 minutes?
Questions like these rattled around the mind of Lorimer Moseley when he showed up at Sydney's Royal North Shore hospital years ago as an undergraduate physiotherapy student. He wanted to interrogate a quip made by a neurology professor as he left the lecture theatre one day, that the worst injuries are often the least painful. So Moseley sat in the emergency room and watched people come in, recording their injuries and asking them how much they hurt.
'And this guy came in with a hammer stuck in his neck – the curly bit had got in the back and was coming out the front and blood was pouring all down,' Moseley recalls. 'But he was relaxed. He just walked in holding the hammer, relaxed. Totally fine.'
Then the man turned around, hit his knee on a low table and began jumping up and down at the pain of the small knock.
'And I think, 'Whoa, what is happening there?''
The curious student ruled out drugs, alcohol, shock. He realised that the reason the man did not feel pain from his hammer injury was due to the very point of pain itself.
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'Pain is a feeling that motivates us to protect ourselves,' says Moseley, now the chair in physiotherapy and a professor of clinical neurosciences at the University of South Australia.
'One of the beautiful things about pain is that it will motivate us to protect the body part that's in danger, really anatomically specific – it can narrow it right down to a tiny little spot.'
It is an evolutionary self-protection response that meant the man with the hammer in his neck did not appear to feel pain. To feel pain would not have aided his survival in that moment, Moseley says. Instead, fear is probably what impelled him to race to the emergency ward.
'So these people on the battlefield, their arm gets ripped off, they look for their arm, they pick it up, they walk to safety, no arm pain. Perfect. That is an extraordinarily bold and sophisticated protective system.'
Prof Michael Nicholas is used to stories like these. 'You can see it in probably every hospital ward. If you stay around long enough you'll hear comments like 'this person has more pain than they should have' or 'you might be surprised that they're not in pain',' he says. 'What that highlights to me is the general tendency for all of us to think there should be a close relationship between a stimulus like an injury or a noxious event and the degree of pain the person feels.
'In fact, that's generally wrong. But it doesn't stop us believing it.'
The reason we get it wrong, Nicholas says, 'is that we have a sort of mind-body problem'.
Eastern medicine and philosophy has long recognised the interconnectedness of body and mind, and so too did the west in early civilisations. In ancient Greece the Algea, the gods of physical pain, were also gods associated with psychic pain – with grief and distress. But in the 1600s the French philosopher René Descartes set western thinking on a different course, asserting that the mind and body were separate entities.
'In a lot of countries we tend to want to downplay any possible psychological influences and we want to say it's all physical,' says Nicholas, a director at the University of Sydney's Pain Management Research Institute. Being told that pain has a psychological component can be distressing, particularly for those who experience chronic pain. It can feel dismissive, a suggestion that the pain is not real.
'When people come to see me, they're often worried they're being told it's all in their head,' Nicholas says.
'Of course pain is in your head. It's in your brain. You know, it's the brain that is where you get that experience … It's never all physical.'
The true of people who tolerate acute pain. It's never all physical. And it has little to do with heroism or freakishness.
Sometime between 11am and 11.30am on 22 May 2024, as I sat at a big white conference table, before a screen of colleagues zooming into a meeting, a cyst on my right ovary exploded. I felt pain right away. With my right hand, I pressed hard into my lower stomach and breathed in and out slowly to ride through the feeling. Jesus, I thought. I shouldn't have eaten so many Jols.
I returned to my desk but still felt sore so went for a walk around the block to shake it off. I felt a little better, returned to my computer, popped in and out of smaller meetings, answered emails, edited articles, finished work at 5.30pm, then walked half an hour to my sister's apartment and lay on her couch. While the pain was fairly strong I was still convinced an overconsumption of sugar-free sweets was responsible. Only when my sister called a helpline two hours later and a nurse told me to go to hospital did I relent. We arrived at emergency about 9pm, 10 hours after that first sharp twinge.
Later in the night, as I climbed on to an examination bed, I froze. Pain sloshing around my abdomen violently halted my movement. As I stopped there silent, halfway to laying down, I saw the serious look on the doctor's face.
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I realised that perhaps my report of my pain was an unreliable guide. She was looking for other clues. (I would later learn that medical staff use self-reported pain as only one of a few measures to assess a patient, others include observations of movement, the ability to talk, facial expressions and guarding.)
It was the middle of the night before an MRI returned the findings that I had spent the day with what the doctor called 'a belly full of blood'. The next day I had surgery.
At my bedside an obstetric surgeon shook his head as he explained what was going on in my body. A burst cyst has a reputation for being very painful, he said. Why had I rated my pain as a six or seven? Didn't it make more sense to give it a 10? I shrugged. I'd wanted to give myself some wriggle room.
So why was my experience and report of pain so out of whack with the tissue damage my body experienced?
'It actually starts with our judgments,' says Associate Prof Melissa Day, from the University of Queensland. 'So it's not what happens to us. It's how we judge what happens to us.'
In other words, if we give ourselves a convincing explanation for what we feel, an explanation that does not include danger or damage to our body – if we think it's the Jols and it will pass – we are less likely to feel pain severely.
We have a tendency to valorise those who do not complain of pain when they confront an acute injury. To say this is a tough person, a stoic person. But individual toughness or weakness is not what's at play in pain responses, and the same person can have two entirely different reactions to pain-inducing events in different contexts.
When Lorimer Moseley tried a heat pad pain test on himself, increasing the temperature on the pad on his hand and noting his rising pain levels, it took removing the pad from his skin to realise he had given himself two-and-a-half-degree burn. 'This happens to people who do a lot of pain research because you just get exposed and your brain doesn't think it's worth protecting you as much as it should,' he says.
'But I put my hand in hot water to do the dishes – I'm hopeless.'
Just five years ago the International Association for the Study of Pain revised its definition of pain. The new definition follows what is called a bio-psychosocial model, which recognises not just the biological causes of pain but the role of psychology and social context in creating, amplifying – or dulling – it. While this is the contemporary thinking about pain, says Nicholas: 'Most people don't use it. Most clinicians, unfortunately, even.'
The biological causes are clearest. Pain tolerance, researchers speaking to Guardian Australia say, has some genetic component. Red-haired people, for example, Moseley says, have on average a different threshold at which their nerves are triggered by a change in temperature in a heat-based pain threshold test.
Complex social factors play a substantial role: multiple studies have found that people from a lower socioeconomic status experience both more chronic pain and, in experimental pain tests, demonstrate lower acute pain thresholds.
For all people, injury or tissue damage activates the brain's warning system that creates pain. The associated stress can trigger a psycho-biological response that helps the hurt person get through it without being immobilised.
'Short-term stress actually motivates us,' Day says. 'Gets adrenaline pumping through our bodies, allows us to have natural endorphins to push through. There's also endogenous opioids that our brain releases to have that short-term relief of pain.'
The psychological elements are becoming more widely understood. 'One thing we know is perhaps the strongest predictor of pain tolerance is how people think about pain,' Day says.
'If we think 'this is terrible, this is awful, it's going to do me serious damage' – those types of people will have lower tolerance.' This includes people who tend to be anxious or who catastrophise pain.
The perception of the damage being done can have a substantial role. A violinist is more likely to report higher levels of pain when a pain stimulus is applied to their dominant playing hand than when their other hand is subjected to the same stimulus, Moseley says – because an injury to their dominant hand could end their career. Farmers are known to delay seeking treatment , he adds. 'It might be that farmers expect that a part of being a farmer is to have pain. So [their brain] doesn't urge them to do anything about it. Their expectation is: you have pain.'
Our past experience of pain also plays a substantial role. Should I have another cyst explode, Moseley suggests I might feel more pain – I will have learned that this sensation signals serious damage and should not be ignored.
Research suggests men generally have higher pain thresholds than women. Pain fluctuates for women at periods of hormonal change. Moseley says differences in sensitivity in immune systems and response to hormones plays a part. But so does 'the way that they're related to from birth'.
'Nature versus nurture – you can't really separate them,' Day says. 'There's a range of factors there in terms of learning histories about pain and how from a young age responses to pain are very much linked to gender as well – how parents respond to a son versus a daughter.'
As psychologists working in pain, Day and Nicholas are interested in what behaviours might help people in pain tolerate or reduce the amount of pain they are experiencing.
'The best coping techniques will be different for different individuals and will be different across different contexts' Day says.
Nevertheless, for acute pain suppression – 'I'm not thinking about this because I've got this goal I need to achieve' – can work well in the short term, says Day. ('Longer term, it rebounds.') Emotional regulation strategies, meditation and learning how to calm the body can be effective. Working on beliefs about the pain and shifting attention away from it, says Nicholas, fall under individual control. 'If you can control those factors you will have a better response to pain,' Day says.
An individual's sensitivity to reward and punishment plays a role in acute pain thresholds too, Day says. People who are more sensitive to punishment tend more often to retract at the appearance of pain, whereas those more oriented towards rewards are more likely to push through it to achieve a goal, she says. Elite athletes are known to have higher pain thresholds as they are habituated to pain in their training regimes.
Which is to say, if you are in a grand final and you think you've got a shot at winning, and you know the national team selectors are watching, your fixation on your goal might increase your ability to ignore the pain radiating from your jaw.
Is that what made John Sattler play on? I will never know. He died in 2023. But we know he had all the predispositions for withstanding acute injury: he was habituated to pain as an athlete in a game famed for its big hits, he was reward-oriented in a moment when the stakes were high, he was a male socialised to value withstanding pain as a badge of toughness, and saw toughness valued as a social virtue. The clash would have got his endogenous opioids pumping. His attention was redirected away from his injury. Pain is a protective mechanism but, from all we know about that day, Sattler judged protecting his jaw as less important than claiming the premiership.
'People who think they have a higher pain threshold – we will never know,' Moseley says. 'It's the same human that makes the pain and that tolerates it.'
And so the experience of acute pain is caught in the realm of mystery and mythology; where we can understand much of what is happening in a body and part of what is happening in a brain but never actually know what another person feels.
The legend of John Sattler goes that after that fateful right hook from Bucknall, the bloodied captain turned to his teammate Matthew Cleary. That no one knew, perhaps not even himself, the damage that had been done to him became his mythological power.
'Hold me up,' he said. 'So they don't know I'm hurt.'