How and Why Do We Feel Pain?
Each one of us has felt pain in our lives. It’s something all humans have to experience from the day that they are born. Whether it’s a stomach ache that causes one to miss lessons exactly before a review or a blistering headache right after a standard test, everyone has had to deal with feeling discomfort.
First, we need to understand “pain”. The International Association for the Study of Pain defines it as an “unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage”. It looks knotty, but simply, pain is an unpleasant sensation which hints towards some damage.
What most people don’t comprehend is how invaluable the sensation of pain is to the human body. Typically, if the brain registers pain, the cause of that is promptly cut short, thus preventing further harm. Taking an example, athlete Usain Bolt could rupture his hamstring while sprinting. The subsequent agony would stop him from using his legs, which would impede any serious harm to his legs. However, without the sensation of pain, he would not realise that something is wrong. Therefore, pain is the body’s way of ceasing any attempt of the body to cause further suffering by preventing movement.
In the body, the nervous system identifies pain sensations. Special pain receptors called nociceptor activate at the site of injury. These receptors transmit information in the form of electrical impulses through nerve cells to the dorsal horn in the spinal cord. From here, it passes the signals onto a specific region of the brain called the thalamus. This is a sorting station that relays the signals on to distinct parts of the brain. Signals are sent to the somatosensory cortex (responsible for physical sensation), the frontal cortex (in charge of thinking), and the limbic system (linked to emotions). The result amounts to one feeling the pain physically and then reacting physically and emotionally, all in a matter of milliseconds.
Distinct types of pains are carried by different nerve fibres causing varying sensations. For example, pricking pain is carried by A-delta fibres while dull throbbing pain travels via C fibres. A-delta fibres conduct signals faster than C fibres which explains why, on pricking your finger, the first type of pain you feel is a sharp sensation (‘fast pain’, carried by the A-delta fibres), followed by a slower spreading ache (‘slow pain’, carried by the slower C fibres).
While it may seem straightforward, detecting pain is intricate because it is not a one-way system. It isn’t even a two-way system. Pain is more than just cause and effect. It is affected by everything else that is going on in the nervous system. One’s mood, experiences, and expectations can all diversify the way pain is interpreted at any given moment. In fact, there is a strong link between depression and chronic pain.
Eventually, Everyone must learn how to grapple with pain. While it may be a ‘pain’, hopefully now that’s its importance and working is known, it can become an acceptable part of life!
– Aarush Shah