Have you ever visited your physiotherapist for shoulder pain and they started to treat your neck? or have you had pain down the back of your leg and been told that it was actually coming from your lower back? Perhaps you have even heard of the strange phenomenon where amputees continue to feel pain in the place where their limbs used to be. If you have ever experienced something like this it can make you wonder if your mind is playing tricks on you.
WHY DOES THIS HAPPEN?
The truth is we still don’t understand everything about the way pain is processed. Usually something causes damage to the body and a signal is sent up to the brain which tries to make sense of where that damage in coming from. Occasionally something goes a little wrong and the message gets confused. This phenomenon is called “referred pain” and can happen for a few different reasons.
Some referred pain is easy to explain. The nerves in our body run like electrical cords out from the spine to the tips of our fingers and toes, branching off to send and receive signals from different parts of the body. If the nerve becomes injured or irritated the pain can continue along the course of the nerve. This will feel like a sharp burning pain that runs like a strip, often along the skin. The most commonly experienced example of this is Sciatica, where the large nerve that runs down the back of the leg is irritated at its origin, in the lower pack. However instead of pain being felt in the back there is a distinctive pattern of pain down the leg.
In other cases it is not the nerves but muscles that refer pain elsewhere. This case is slightly more difficult to understand but can be explained by muscular trigger points. These are taut bands that develop within muscle tissue that is undergoing abnormal stress. Poor posture, lack of movement and overuse are just a few things that cause muscles to work abnormally and eventually develop points of stress. These trigger points can cause pain that radiates out in distinctive patterns. Trigger points can be diagnosed as the source of pain if symptoms can be reproduced when a therapist presses on a specific point. Treatment of trigger points can cause pain in a distinct location to disappear.
If that wasn’t confusing enough, we know that our internal organs also refer pain. This is the most difficult type of referred pain to understand as our organs distribute pain in patterns that are very obscure and sometimes don’t even create pain at their own site. Tragically some people don’t realise they are having a heart attack because they feel pain in their neck and arm and not in their chest. Pain referred by internal organs is frequently described as a deep ache and usually not influenced by movement of the limbs or back.
There are many other fascinating aspects to pain and understanding how it works is an important part of managing your symptoms. To understand how referred pain may be affecting you, chat to your physiotherapist who can help with any questions.