For a long time, we viewed pain as a relatively simple system. In fact, it is more complex than it appears. Pain serves as a useful alarm because, in cases of potential injury, it is often what alerts us and protects our physical integrity by motivating us to take action. But is this alarm infallible?
Pain acts as an alarm system
According to the official definition of the IASP (International Association for the Study of Pain), pain is “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.”
In simple terms, pain acts as an alarm system in response to danger.
This system is very important, even vital! Some people do not feel pain; this condition is called congenital insensitivity (or congenital analgesia). It is very problematic for the person because it inhibits all the mechanisms that the brain puts in place to respond to pain. Imagine, for example, that you run a bath with water that is too hot. You will immediately pull your little toe out of the water. But people with analgesia will be able to immerse themselves completely in the water, without even feeling that the water is too hot against their skin. [1]
Did you know? Pain is not proportional to the severity of the injury (e.g., a surfer who has his leg torn off does not feel pain immediately, but only after reaching the beach, or even never). Conversely, a person who cuts his little finger with a sheet of paper may feel intense pain.
You can also feel pain in an amputated limb; this is called phantom limb pain. [2]
To describe the pain pathway in simple terms, let's take the example of accidentally placing your hand on a hot plate. The heat will initially stimulate the nerve endings without necessarily causing a burn. These endings, located in the skin (called nociceptors, which are also found in muscles, joints, etc.), will send information via cables (nerves) to our brain.
Once the information reaches the brain, depending on all the other information it receives, it will produce pain or other responses such as increased muscle contraction, increased heart rate, and sometimes even opposite responses such as pleasant sensations.
Did you know? In this specific example, the hand was removed before the heat signal was even decoded by the brain! This phenomenon is due to a reflex arc in the spinal cord, which is where the first pain modulation systems are located. [3]
Acute pain therefore plays an important role in protecting our body, controlled by our brain.
The alarm system is not always foolproof
The alarm system described above can be malfunctioning. Several researchers and the International Association for the Study of Pain believe that these malfunctions could explain the persistence of certain types of pain. When pain persists for more than three months, it is referred to as “chronic pain.”
The alarm continues to sound even though there is no longer any danger to the body, or the threshold for this alarm is very low and is therefore triggered quickly.
The pain is very real, but it is the alarm that is malfunctioning. The good news is that this hypersensitivity to pain is a reversible process and that we can influence our brain and the rest of our nervous system. It is therefore possible to shape and strengthen it through appropriate exercises and thus develop a greater ability to do things comfortably
Let's remember that:
- Pain acts as an alarm system that enables us to survive
- It is the brain that produces pain or not
- This system is not foolproof and can be disrupted
Sources
[1] Vlaeyen, Johan W.S.*; Crombez, Geert; Linton, Steven J. The fear-avoidance model of pain https://journals.lww.com/pain/Fulltext/2016/08000/The_fear_avoidance_model_of_pain.5.aspx
[3] https://www.inserm.fr/dossier/douleur/#:~:text=Selon%20la%20d%C3%A9finition%20officielle%20de,ou%20d%C3%A9crite%20dans%20ces%20termes%22.