What is Pain?
Pain affects us all and is a protective mechanism to help us avoid real or perceived danger and can be very helpful for our survival.
Sometimes pain can last longer than anticipated. Some people end up living with pain for several years and can seriously affect your everyday living. To help improve pain and not let it take over your life, it is important to understand what pain is and how it can become persistent.
Pain is an output of our brain. It is our brain that decides if we experience pain or not. Pain is not sent from the body to the brain.
Until relatively recently we thought the French philosopher Renes Descartes was right when he proposed that when a body part was damaged it sent a pain signal to the brain to say "I'm in pain".
We now know Descartes was wrong. In fact, sometimes you can significantly damage your body and feel no pain at all. It is not until the brain decides "right, we're in danger so I'm going to motivate you to do something about it" that you feel pain. Mostly the brain gets it right, but sometimes the brain gets it wrong!
Explaining the nervous system
To explain this further let’s first take a closer look at the nervous system. If you added all the nerves in the nervous system together, end to end, an average sized adult's nerves would reach nearly 45 miles! Together they form a remarkable network of communication that moves us, makes us feel, hear and see things and generally lets us do everything we do.
Secondly, consider that our brain constantly receives signals from all over our body and uses this information, along with our parts of the brain such as memory and emotional centres, to answer the question "are we in danger?"
For an example, let’s think about a sprained ankle. When we sprain an ankle, nerve endings in our ankle fire and send signals up our leg to our spinal cord. If the spinal cord receives enough of these signals then it decides it is important enough to send it up to the brain.
Our brain uses this information in lots of ways:
- It will access the memory part of the brain to see if we have received information like this before
- It will use visual cues like what that area of the body looks like (e.g. Does it look in a funny position?)
- It will also use sounds we hear like a ligament pop
Our brain then puts all this information together very quickly and decides if we are in danger. If the brain's conclusion is "yes" then we feel pain, if it is "no" then we do not feel pain.
If the brain believes we are in danger it will use pain as a motivator to try to get us out of danger. This is why pain can be understood as helpful for our survival.
Therefore, whether we have a recent 'acute' injury or a problem that has lasted for several months or years, pain is, 100% of the time, produced in the brain.
As stated though the brain doesn't always get it right and we feel pain despite there no longer being an injury or danger. Some important points to consider are:
• Pain does not indicate severity of injury – think paper cut.
• Sometimes lots of damage can result in no pain – think car accident anecdotes.
• Sometimes no damage can result in lots of pain – some spinal issues upsetting nerves.
• Sometimes an injury can heal and we still feel pain – phantom limb pain after amputation.
It depends what our brain decides.
Persisting or 'chronic' pain can be influenced by many things. Recent imaging of the brain has shown that stress, memory, anxiety and depression can all influence pain and turn the pain levels up and down.
How do you treat pain?
As physiotherapists we take an accurate and detailed history and assessment with persisting pain problems to determine what the main cause is and what would be the best management strategy to take.
Management can involve your regular physiotherapy interventions such as manual therapy (treating stiffness, tight muscles and sensitive nerves) and exercise.
However, it is also important to identify things you might be doing day to day that could be accidentally contributing to the problem. Often your own beliefs about what is causing the pain can be inaccurate and, these beliefs, if they are unhelpful, need to be challenged.
For example, someone might believe they have "slipped a disc". You actually can't slip a disc, your disc can swell like a swollen knee but the disc does not slip out or back in. Some patients can become very debilitated by the belief that their disc is ‘out’ and this itself drives the brain to perceive pain even after the disc has returned to normal.
Sometimes we move in ways that may also aggravate the problem without realising it. The habitual limp when the ankle sprain is actually better, for example, gives the brain false information to work from because it associates that movement pattern with pain - so therefore it must hurt…..
Stress is produced by the brain and directly affects the ‘sensitivity’ of the brain, often heightening the perception of pain.
Stress is produced by the brain and directly affects the ‘sensitivity’ of the brain, often heightening the perception of pain. Stress therefore needs to be identified and possible interventions can include appropriate medication from your GP in the short term to tone the brain response down, or psychological intervention to help you find ways of dealing with stress, anxiety and depression and challenging those unhelpful thought patterns.
The bottom line is that brain will use all of its resources to protect us. Many things can influence pain from our memories, to our emotions, the environment we are in at the time and our own worries about the pain.
Physiotherapists aim to help people in pain whether it be acute (recent pain) or chronic (persisting) pain. Your physiotherapist will work with you to understand what the main cause of your pain is and what factors may be contributing to your pain even when an injury has had plenty of time to heal.
Don’t think pain is all in your head. It is…. but not in a negative way. You are not odd or a looney if you are feeling things that don’t add up. It can just be the brain has got a bit mixed up. Seek help and don’t ignore it.