You’re walking to the bathroom in the middle of the night when suddenly- whack! Your toe clips the door stop. Typing it even makes me cringe. That’s acute pain. The sensation that occurs to let us know that something potentially dangerous is happening at a point in our body in the moment. We need this sensation to keep our body parts safe and avoid allowing them to dangle in a vat of boiling water or allow the rusty nail to hang out for a week in our foot, leading to bigger problems. However, there’s a whole different category of pain that plagues a huge portion of Americans- chronic pain. This is pain that is present for greater than 3 months and leads to disability and time away from work and recreational activities and costs the healthcare system hundreds of thousands of dollars. So what’s going on in chronic pain? We’re not kicking the door stop for 3 consistent months. In fact, oftentimes chronic pain leads to people spending long periods of time resting, seemingly as far out of the way of danger as possible. So why is the pain still there?
The answer to this question is actually astoundingly complicated, but we can try to skim the surface.
Imagine that all of the nerves in your body are always in listening mode, buzzing along, looking for something interesting to pick up. When they intercept a big enough sensation or stimulus, it causes them to jolt, rising above a threshold line. This message then sends to the brain. Think back, however, to when you get a papercut or stub your toe particularly hard. Does the pain drop to 0 the second that the stimulus stops? No, it may take a few minutes, hours, or days for that area to stop feeling tender. So that level of nerve activity is slowly lowering back down to normal. But what if a second insult occurs before the sensitivity has returned to its baseline level? Now that jolt rises back up and maybe takes even longer to return down. If a body part has sustained multiple insults over a relatively short period of time, the nerve will now stay sensitized, near that threshold of alerting the brain at all times. Now it takes hardly any stimulus to get it to jolt up and tell the brain “something’s happening over here again!!” It may start alerting the brain for completely innocuous changes like soft touch, stress, hot or cold, or changes in joint positioning. All these things now rise above that threshold and the brain thinks “oh no- we’re in trouble again- code it as pain!” This person now thinks that any occurrence at the body part means danger and may limit their activity to try to avoid hurting themselves.
The important thing to know is that the experience of pain does not always indicate that tissues are in trouble. In the case of long term, chronic pain, it means that your alarm system is malfunctioning. Lowering pain does not arise solely from healing the body part, which is certainly happening over time, but also requires fixing the alarm system. Your physical therapist will work to improve the health of the painful body part with exercise, postural changes, manual therapy, etc. However, she will likely also recommend alarm-fixing strategies that may at first not seem like a priority when you’re trying to feel better. However, these interventions are integral in achieving lowered pain. These are things like deep breathing, meditation, gentle movements or exercise to bring more blood and nutrients to the area, and simply understanding this alarm system phenomenon. As the resting nerve excitement lowers, greater movement and activity can be performed without triggering the alarm and the person is able to get back to work, fun, and feeling like themselves.