What do we really know about pain?
Pain is one of those “you know it when you feel it” kind of
sensations. But it’s also a strange phenomenon, when you think about it. A snowball is cold, and so it feels cold when you touch it. A block of concrete is rough, so it feels rough when you touch it. But a knife isn’t painful on its own. Neither is a pot of boiling water or the leg of a table. We handle these things safely all the time, and experience their mass and temperature and texture. But pain exists only in the body, and even more specifically (as people who’ve experienced anesthesia know firsthand) in our minds. But that doesn’t make it less real! So what exactly is happening when we feel pain, and how do we stop it from negatively impacting our lives?
How does pain work? There are three primary types of pain, and each of them works a slightly different way.
Nociceptive pain (tissue pain) There are many different kinds of sense receptors in the body. Some are sensitive to heat or cold, some to touch or pressure. Others, called free nerve endings, aren’t specialized for any one type of stimulus. When a significant stimulus triggers these nerve endings, they send a message through the spinal cord and up to the brain indicating that something potentially dangerous has happened. The brain then decides (without consulting the part involved in conscious thought, alas) whether this is something to ignore or brush off or if it seems likely that damage has occurred. This then sends this message back down to the affected part of the body.
If the message is “No biggie, ‘tis but a scratch,” then you’ll most likely shake yourself off and forget the incident even happened. If it’s “WHOA, THIS SEEMS LIKE A PROBLEM,” then you experience this as pain.
This is useful! Just ask someone with CIPA, or congenital insensitivity to pain with anhidrosis, a disease that leaves people insensitive to pain. Imagine not noticing a bit of grit in your eye until it damages your cornea, developing stress fractures in your feet because nothing is telling you it’s time to sit down, or ending up with burns in your mouth and throat because you don’t realize your coffee is scalding hot. Pain stops us from trying to walk on a sprained ankle or go for a run when we have a fever. Tissue damage, high temperatures, low pH, and capsaicin (the active ingredient in hot peppers) are all common triggers for this process.
But brains aren’t always correct when it comes to assessing danger. Lorimer Moseley gives a brilliant example of this in his TEDx talk. What’s the difference between the pain from a scratch on the leg and the pain from a nearly-fatal snake bite? Spoiler: it’s whatever your brain is expecting. That’s why you might feel little pain after a bicycle accident, but be in agony when getting the wound stitched up two hours later. Pain is weird.
Neuropathic pain (nerve pain) This is pain that results from an issue with the nervous system itself, rather than surrounding tissues. If you’ve ever banged your funny bone, you know this feeling well. Common forms of neuropathic pain include:
~ Sciatica: pain in the sciatic nerve running through the hip and down into the leg and foot ~ Diabetic neuropathy: nerve damage resulting from fluctuating blood sugar levels ~ Carpal tunnel syndrome: pain resulting from the compression of the nerves that run through the wrist into the hand
Less common forms include phantom limb pain (pain that feels like it originates in an amputated limb) and postherpetic neuralgia, which occurs as a result of getting shingles.
Neuropathic pain can be especially frustrating because the normal things we do to reduce pain are often useless when it comes to pain originating in the nervous system. Moving or not moving our muscles, applying heat or ice, these can have relatively little impact on nerve pain. What’s more, nerves don’t heal as well as things like muscles and skin do, which makes nerve pain more likely to become chronic pain.
Other pain Pain is messy, and a lot of it doesn’t fall into either of the two categories above. Fibromyalgia is a great example of this. Is it pain resulting from tissue damage? Nope. What about nerve damage? Not as far as we can tell. It’s caused by the nervous system malfunctioning, sometimes in horrible ways, but that don’t result from actual nerve damage. Often a lot of it. And the world of medicine is still trying to figure out why.
So how do we alleviate pain? There are several different options.
If the pain is caused by some kind of physical injury or stimulus, you can work on fixing that. If your hand is being burned on a lightbulb, you can remove your hand, which will make most of that pain go away. If you’re experiencing a muscle cramp in your foot, you can flex the foot (manually, if necessary). If you’re experiencing pain from sitting in the same position for too long, you can move around and shake out your legs. If the cause of the pain is inflammation, anti-inflammatories and ice can reduce that. This is perhaps the ideal form of pain relief, although it’s not always in the realm of the possible.
You can block the messages that tell your brain you’re in pain. This is how many painkillers work. Ice can also numb nerve endings.
You can convince your brain that you’re not in any real danger. This is a tough one, because the brain doesn’t just listen when you tell it things. But it’s well documented that fear, stress, and anxiety lead to increased pain perception. And of course, pain leads to stress, which leads to pain …General relaxation techniques—from meditation to light exercise to getting a massage—can all be helpful in turning the brain’s pain alarms down a notch. Physical therapy (practicing certain motions in a way that isn’t painful) and talk therapy can also be useful here too.
How can massage help with pain? Sometimes the issue is one that massage can help manage on a physical level. Deep tissue massage helps with chronic muscular pain and injury rehabilitation, and reduces inflammation related pain (ie arthritis, tendinitis). Trigger point therapy uses focused, sustained pressure to interrupt the neural signals that cause pain. But even more often, massage gives the brain a chance to let down its guard and experience something non-painful and even pleasant in the body. And while there’s no silver bullet for pain, that can mean a lot for people whose pain has defied more straightforward treatments and whose injuries or illnesses are already healed.