Pain is something that humanity has constantly tried to define… but it is not easy. I warn you that the Taxonomy Subcommittee of the International Association for the Study of Pain (IASP) It took two years of deliberations to arrive at a definition in 1978. Part of the mystery is that pain It is more than biological.
Although undoubtedly is a feeling in a part or parts of the body, is always unpleasant and, therefore, is also an emotional experience. In the end, the IASP managed to arrive at a definition, which was revised in 2018, and widely accepted by health professionals and researchers in the field of pain, and adopted by several organizations, including the World Health Organization (WHO).
The pain is “an unpleasant sensory and emotional experience associated with, or similar to, that associated with actual or potential tissue damage”. But not all pain is the same. “There are a large number of different pains, and each person’s pain is different,” the neuroscientist and pain expert told BBC Mundo. Maria Fitzgerard“but they have been categorized into three types.”
This is according to pathophysiology, which studies the alterations in the different functions of the human body to understand the reason for the appearance of various diseases. According to the IASP “pain can be classified as nociceptive, neuropathic or, in the case of chronic pain only, central sensitizationdepending on the type of injury and the pathophysiological pathway that leads to the perception of pain.”
Of those three, there is one type that, although it makes us suffer, tends to be useful, and another two that I hope you never feel.
nociceptive pain It is the type of pain that you surely know, although perhaps you did not know the name. Under it are groupedmost of the pains we feelthe most common, the ones that are resolved,” he explained Fitzgerald.
They are those that are producedbecause some tissue, some part of your body, was injured”. He added: “You might have a bruise, or you might have broken your arm, or you might even have swollen joints like with arthritis, but basically something is hurt and that triggers pain. It’s horrible, but you know what it is”.
These types of pain “are part of the protection of our bodywhich makes us rest, protect the area and help it heal,” said the University College London expert.
So of these pains, we know what is the cause and what is the purpose. “They can be annoying, but they are very important: a life without pain would be very dangerous and potentially deadly“, hill.
“Neuropathic pain is really intenseFitzgerald noted. It is a complex type of pain caused by an injury or illness that affects the central nervous system, which is responsible for carrying information to the brain.
It is estimated to affect approximately one in 20 people in the Western world, according to the Royal Society of Medicine British. One of them, the BBC radio host and presenter Fiona Talkingtonhas described it as “the loudest scream that no one hears”.
“That kind of pain can be horrible because it doesn’t feel normalFitzgerald said. “If I were to tell you what my pain is like right now, it feels like someone tried to put me in a scuba suit covered in little bedbugs.” very very sharp” Talkington told BBC Ideas and the Royal Society. And he continued on a more precise example: “It also feels like there are people drilling into the soles of my feet, and my legs feel very tight.”
Talkington often talks about his experience of living with painful neuropathies since undergoing chemotherapy to treat breast cancer in 2008, in hopes of encouraging a broader understanding of that type of pain and its often devastating effectsin people’s life.
At other times, Talkington, as well as others affected, describe the pain as if they were burning, or a part of their body was frozen, or they were receiving electric shocks; Sometimes a light touch can cause intense pain while other times you don’t feel anything.
“Clinical pain experts can immediately identify neuropathic pain because of these terrible descriptors. Often these pains are not really a clear sign of healing, since nothing is being healed, only They cause a lot, a lot of sufferingFitzgerald noted.
And for now, there is no remedy, only relief. “There are great attempts and a lot of research to try to prevent the nervous system from creating these pains. Many people are working very hard on it, but it has not been resolved, unfortunately, so it’s a matter of trying to make them less unbearable“explained the specialist.
The cause of these pains is known, but the purpose is not understood.
In the previous two types, pain is not an independent ailment, but the body’s response to other events: a sign that something is wrong. But that view excludes many patients, whose pain has no obvious source.
This is the case, for example, of those who suffer from fibromyalgiaa condition whose symptoms are widespread chronic painfatigue, sleep difficulties, decreased physical functioning, mood disturbances, and cognitive dysfunction that can include problems with memory, concentration and mental clarity.
“There are people who wake up in the morning and they feel like everything hurts, and that the pain is not in a particular area. And they often experiment with what they call ‘niebla cerebral’the feeling that they can’t think straight,” Fitzgerald said.
“It is probably generated centrally, by the brain, but that does not mean it is a psychiatric condition. Something about the way pain is processed in the brain has been altered so that they feel pain when there is no damage, and that It’s very difficult to cope”, he pointed out.
Like this, there are other ailments for which “there is no biological source”. It is not a swollen joint or a severed nerve. “That doesn’t in any way mean it’s not real. It is 100% real. It’s just that our understanding of our bodies remains limited. That is the third type of pain, which really is a mystery”, he explained to give it a theoretical framework.
In this case, both the cause and purpose are unknown. Despite the enigma, “science began to realize that you can’t always find an injury when someone is in a lot of pain, and instead of doctors telling patients to leave because there was nothing wrong with them, They recognized that they were suffering,” Fitzgerald explained.
This opened the way to the possibility of considering that “pain itself is a disease”. But one more step was needed, and it was taken by the joint IASP and WHO working group, which developed the 11th International Classification of Diseases.
It came into force in 2022 and included a novel concept Originating from the idea that long-term diseases or conditions associated with chronic pain should be recognized in their own right, even if a clear understanding of the underlying causes is lacking.
They called him primary chronic paindefined as: a chronic pain, since persists for more than three monthsin one or more anatomical regions, which is characterized by a emotional discomfort significant (anxiety, anger/frustration, or depressed mood) or functional disability (interference in activities of daily living and reduced participation in social roles); and the symptoms are not better explained by another diagnosis.
In the IASP pain classification, according to the pathophysiology, it is called “central sensitization (also known as nociplastic pain)”. Both this type of pain and neuropathic pain, in addition to worrying, intrigue Fitzgerald. “I think the remaining mystery is Why do a substantial number of the population suffer from pain for no obvious biological purpose?”, he concluded.
By Dalia Ventura, for BBC Mundo.
