Anything but the same: pain perception for men and women
We all know about pain. It is a tool which informs us about the state of our body. For a long time, it was thought that men and women are about the same when it comes to perceiving pain. New research is casting doubt on this picture. More and more differences are coming to light. What do we know about this and what are the possible reasons?
What exactly is pain? A definition
John Bonica, an American anaesthetist who is considered the founder of modern pain medicine, offers the following description:
“An uncomfortable sensory and emotional experience, which is accompanied by actual or potential tissue damage or is described in terms of this kind of damage.”
Pain is therefore an uncomfortable sensation, which can be attributed to (actual or perceived) damage to the body or soul of the person.
Useful pain in the course of our development
If we take a few steps back in natural history, we can see that pain is a very old phenomenon: pain has existed as long as there have been powerful nervous systems. And pain never appears by itself. It is always linked with an additional signal which gives us information about its origin. In this way, we usually experience a feeling of pressure, hot or cold sensations, or stinging as well as the pain. In addition, we generally also receive information on exactly where the pain is occurring.
Pain acts as a kind of ‘early warning system’. It is meant to urge us to avoid, limit, or end a situation which is either currently harming us or which would harm us if it continued long-term. Pain has always been useful to humans for our survival. Because of pain, we pull our hand away from fire, jump back from thorny hedges, and do not walk over sharp stones with bare feet – lots of types of behaviour, which prevent potential damage to our body.
Additionally, there is a constant learning process. Through experiences of pain, we learn to look out for similar sources of danger in future and can even pass on this knowledge to our descendants – a fact which gives humans a big advantage in the context of evolution, the ongoing development of all life.
Not all pain is the same
For a long time, it was thought that the perception as well as the effect of pain was the same for men and women. However, there is growing evidence that this is not the case. Fundamentally, there seem to be significant differences between the sexes concerning the so-called “nociceptors”, i.e. pain perception. The term stems from the Latin verb “nocere” which translates as “to harm”. The sensory cells which are responsible for pain perception send signals to our nervous system when tissue damage is imminent or has already occurred, thereby triggering a reaction which averts this danger.
It was already demonstrated in 2006 that there are differences between men and women in the perception of thermal (hot and cold), electrical, chemical, and pressure stimuli. This was evident in relation to two particular thresholds: first, the point at which a stimulus is first perceived as pain and second, the point at which the stimulus is no longer tolerated by the participants (in other words, the point at which the hand is pulled back from the stove top which is heating up). All of the studies consistently showed that the thresholds were lower for female individuals. This means that, for women, sensitivity to pain was higher and pain tolerance was lower.
But what is the reason for this difference? A scientist from the University of Oxford came to the conclusion in 2021 that women generally have a higher risk of developing chronic pain than men. He states that this can be observed with head and back pain in particular. The author gave a range of possible reasons for this; the influence of hormones on the occurrence of pain seems to be particularly important. According to this, sex hormones affect the processes in our nervous system which are involved in processing pain signals. Additionally, these hormones influence functions in our immune system, which also affect pain perception.
How men and women change their behaviour when in pain
Differences between men and women can be observed not just in the development of pain, but also in the approaches to it. In 2019, a study was able to show that, for men, the issue of “injury” is paramount when it comes to pain: the feeling of being robbed of their invulnerability through the experience of pain was described much more powerfully by the male test subjects than was the case for the female test subjects. According to the study, a typical male strategy for handling feelings of pain and vulnerability that can be described as “activity pacing” can be observed. This refers to a reduction of activities as well as taking more breaks, corresponding to the particular pain situation. It is noteworthy that women tend to do the exact opposite when they feel pain, namely overexert themselves, carry out their plans as intended despite the pain (i.e. overdoing it). Therefore, there is an increase in activity for women and a decrease in activity for men.
Pain strategies in light of human development
If we take a look at the beginnings of humanity, we find an indication as to how evolution might have contributed to these different handling strategies. According to our understanding today, the distribution of roles at the time looked something like this: in hunter-gatherer times, the man would provide food for his family by hunting, while the women was entrusted with for caring for the offspring. Let us now imagine that the hunter is injured or sick. In this unfortunate situation, it is important to ensure that their strength is recovered quickly. If the hunter is inactive for too long, the whole family will starve. The harshness of the wilderness in hunter-gatherer times meant that only a hunter who was at full strength could hunt successfully. The quickest possible, sustainable recovery was therefore the priority. All activities which hindered this goal needed to be suspended.
Wie Männer und Frauen unterschiedliche Konsequenzen aus Schmerzen ziehen
However, things were completely different for the female members of the family who were responsible for taking care of the children: the offspring needed to be looked after constantly in order for them to survive and caring for the children, if it was to be successful, did not allow for long breaks at any point.
Self-exploitation as a dead end?
It could be argued that the family does not benefit from the children’s caregiver burning the candle at both ends and therefore, while fulfilling their role in the short-term, not being able to survive healthily in the long run. What does it achieve if the family’s continued existence is in fact ultimately potentially endangered through prolonged self-exploitation? The answer is that, from an evolutionary perspective, it is simply not important for particular individuals within a species to lead a long, healthy life. The only thing that counts is the continuation of the species. This is guaranteed by producing enough offspring.
Selbstausbeutung als evolutionäre Sackgasse?
Simply put: when as many healthy offspring as possible have been brought into the world and have been brought up successfully, so that they can ensure the further continuation of the species themselves, the previous generation has served its purpose. As harsh as this may sound to our ears today: the continued existence of a species is best served when every generation uses their strength and abilities to produce the maximum number of successful offspring.
New strategies for everyone
Today, we are of course no longer living under the conditions of the Stone Age. The fact that, as humans, we do not merely devote ourselves to the continuation of our species can be described as one of the greatest achievements in human development. It is a rule of our – in today’s sense of the word – humane treatment of each other, that each person should be able to have a life which is as free of suffering as possible. For the way we treat pain, this means: wherever possible, the pain should be alleviated rather than endured. Particularly for women, whose pain perception is more sensitive and who are more at risk with regard to the chronification of pain, the guiding principle must be to stop the pain in time. This is even more important when it comes to headaches, which impact female patients significantly more than male patients worldwide.
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