As the saying goes, "All roads lead to Rome." In the human body, all nerves lead to the brain. Nerves are the little electrical wires throughout our bodies that communicate information between our body and our brain. It's fairly similar to a highway system.
Nerves are like a complex network of highways on which electrical impulses of information travel like cars to and from the brain and various tissues in our bodies. This happens at a lightning fast pace, because the impulses are electrically transmitted. Most of the time, our bodies are faster at communicating information than our cars are at driving us home.
There are all kinds of cars that travel in our nervous system with different kinds of messages. Nerves communicate information about light touch, deep pressure, temperature, vibration, body position in space, and whether something is sharp or dull. They also send messages telling our muscles how and when to move. Nerves even transmit information regarding our emotions, taste, sound, smells, and visual images. In short, our nerves are busy places.
The central command center of our nervous systems is the brain. Think of it like one big city, where important things happen. Certain parts of the city have different functions; there are buildings meant for processing emotions, and controlling the movement of our hands. There are centers for language, for visual imagery, and for regulating when we're hungry. Our brains have the difficult task of keeping everything in our bodies running, day and night. They are doing several things to keep us alive, like regulating our heart rate and reminding us to breathe, that we don't think about much. Simultaneously, they also help control the balance and position of our bodies so we don't fall over, process the sounds of the person talking to us, and what facial expressions we see them making.
This involves doing a lot of prioritizing. While our brains are incredible organs and can do a multitude of things, they do have their limits. Our brains can only do so many things at one time. They have to decide on what are the most important things to raise to the level of our conscious thoughts.
For example, your brain knows and receives information about your legs touching your chair constantly, but it chooses to ignore that information to let you focus on the words you are reading. You most likely weren't thinking about your legs touching the chair until you read about it.
Our nervous systems can experience traffic jams, just like cities and highways. Let's say that a large amount of information floods the system all at once, like during a car accident. When in a car accident, there are loud sounds, emotional anxiety and/or anger, and forceful movements to your body. It's also worth considering that immediately before the accident, your nervous system was probably pretty busy. Driving requires us to make a lot of decisions and process a lot of information. Your nervous system was already thinking about directions, watching what different cars were doing, checking the speed of the vehicle, and perhaps listening to the radio.
This is a perfect recipe for a nervous system overload. When too much information floods the system all at once, a traffic jam floods your nerves. This can cause a freezing response in your processing. That's why people are "in shock" after a car accident. They may not realize an injury occurred for several hours because the brain can't process all that information at once.
Traffic jams typically work themselves out eventually, but it can happen a variety of ways. Let's assume first that our car decides to stay on the same path and go through the traffic jam. Sometimes we get stuck in stop and go traffic. This could mean that when you try and tell your muscles what to do, the movement is shaky because the signals aren't getting through smoothly. Or, maybe the traffic was moving smoothly, but slowly. In this case, when you try and tell your muscles to move, your leg might feel heavy, like it's taking more effort to move it than it should because the signals are getting through slower than normal.
Other times, the traffic jam reaches our brains all at once. Our brains may just throw their hands up in the air and say, "I can't process all this!" When that happens, sometimes your brain chooses to process everything as pain. Pain has a very important job in the body, to tell us about danger. Our brains don't want to miss pain, so they sometimes choose to process information as pain when they are overwhelmed. This can be part of why people perceive something as painful that normally wouldn't be. Think about a person with a migraine who has to lay in a quiet dark room because ordinary lights and sounds are painful for them.
In some situations, there is no way around the traffic jam, and so things start to back up. The most common example of this is the person who has lower back pain that radiates down into their leg. The information has such a hard time getting through, that the traffic backs up down the chain and the brain begins to believe that the pain is in a larger area because the traffic is backed up.
In another scenario, perhaps our car decides it's better to take a detour and use the side streets. In this instance, pain can spread. Pain that started in your shoulder may creep up into your neck and give you a headache while your nervous system is trying to find a way around the blockage to get the signals to your brain.
While the analogy of traffic and highways isn't perfect, it can help us to understand why pain isn't always coming from the place we think it is. Our brain's ability to process pain and understand where signals are coming from is a complex process. For more on this, see Invisible Illness: Why Can't My Doctor See My Pain?
This post is intended for educational purposes only and is not intended to replace individual medical advice. If you are interested in scheduling a personal consultation with a doctor of physical therapy, call or select the Book Online option.