A world without pain seems ideal. We don’t feel headaches, sore muscles, or aching joints. No need to worry about pain medications and treatments. If this sounds good to you, think again. What would you feel if you accidentally touch a freaking hot object? Your hands may burn without feeling anything, and your only hint that something’s wrong is seeing a finger getting blistered and red. Does that sound ideal still?
Pain may seem disturbing and annoying, but having the sensation of pain is a way for the body to alert itself of a potential threat that may inflict damage or injury. Understanding the mechanism of pain not only helps in the appreciation of the very essence of its occurrence but also in the development of effective pain relief methods to be able to manage it successfully.
The perception of pain is something that we’re born with. It’s a protective mechanism. We get to think of ways to cope with anything unpleasant when we feel pain from it. It is similar to what we see, hear, taste, or smell but different in the sense that these perceptions are based on things that are happening around us. Pain tells us about the things that are happening inside our bodies.
You feel pain when certain nerves called nociceptors sense tissue damage. These are pain-sensitive nerves that send signals to your brain via the spinal cord that something is wrong going on in your body. Your brain processes this information and responds by making you sense pain.
When you accidentally burn a finger on a hot stove, pain-sensitive nociceptors in your skin are activated through either the A-delta nerve fibers, which are large and myelinated nerves that are responsible for acute sharp pain, or the C nerve fibers, which are small and unmyelinated nerves that are responsible for slow, dull aching pain. Myelin is a sheath that forms around a nerve that enables quicker transmission of nerve signals. The noxious or painful stimulus is converted into a nerve signal or “action potential,” which is then sent up the nerve fiber.
These pain signals are then transmitted from the peripheral to the central nervous system via the spinal cord. Within the spinal cord, electrical signals are transmitted from one neuron to another across junctions by means of neurotransmitters, forming a "synapse" or connection. Signals are then ascended up the spinal cord to the brain primarily within a pathway, the spinothalamic tract.
Modulation is the brain’s way, through the descending pathway, of blocking or altering the intensity of pain signals traveling up the ascending pathway. This is part of the Gate-Control Theory by Melzack and Wall, which states that the application of nonpainful signals via non-nociceptive, larger, and myelinated A‑beta fibers may inhibit or slow down the passage of pain signals produced by the activated nociceptors to the brain.
The nociceptive signals have reached the brain and your brain tells you that your fingers hurt, and then you feel an unpleasant sensation — pain.
However, you’ve probably initially retreated your hand away from the hot object involuntarily by reflex muscle contraction even before the signals haven’t reached the brain yet. This reflex response occurs when motor neurons within the spinal cord are activated, causing your arm muscles to contract and moving your hand away from the painful stimulus.
Pain can be classified as either acute or chronic. If you’re feeling a pain that is intense but short-lived, it’s acute pain. It’s the more common of the two types and is usually associated with specific illnesses or injuries like cuts, sprains, trauma from an accident, or surgery. Acute pain comes suddenly and usually goes away when the underlying cause is resolved. When your pain becomes persistent, it is caused by ongoing tissue damage. This is a chronic pain that can last longer than three months and continue even after the injury or illness that caused it has healed or gone away.
Understanding the underlying cause, presentation, and associated symptoms are key to effectively manage pain and develop strategies that may alleviate it and can improve your quality of life. Pain relief interventions may include the following:
Vibration therapy is another option for pain relief. This can be achieved with whole-body vibration platforms, vibrating massage balls and foam rollers, and recovery tools like massage guns. Mechanical vibration through these devices acts to block the perception of pain by inhibiting the pain receptors' signals transmission of pain to the brain and works via the Gate-Control Theory