If you, or someone that you know, has had chronic pain, this scenario will be familiar.
“I thought my pain was improving – it had been better for two weeks now! My Physio/Osteo/Doctor thought I needed to start exercising and now look what’s happened – I’m back to square one! I mustn’t have been healed, or maybe I’ve re-injured something!”
Intuitively this makes sense – when we injure ourselves, we feel pain. In an acute injury, ie, a new injury, this is true. Unfortunately, if the injury has been present for a while, it ain’t so simple.
In order to understand why flare ups are a normal and expected part of the recovery process in chronic pain, we first need to understand what happens to our bodies when pain persists for a while.
Pain itself is never exactly proportionate to tissue damage. Our tissues, such as muscles, ligaments, tendons and discs have nerve endings, which carry information to our spinal cord and then up to our brain. When we injure ourselves, for example, by rolling our ankle and stretching the ligaments, these nerves relay “danger” messages to our brain, but at this point in time, pain is yet to exist.
Once the information from the injured area reaches the brain, the brain has to decide what to do with it. Our brain takes a look at the “danger” messages from our overstretched ankle ligaments, and tries to understand the context. At this point in time, information coming from our eye nerves and into our brain (I can see the step I just fell off), our emotional centres (“Oh no, my footy final is tomorrow!”) and even our memory (Johnno broke his ankle last year and needed surgery) collaborates with the current “danger” messages from the ankle.
This collaboration of information gives the brain a “big picture” of how dangerous that particular injury seems to be, in that particular point in time, given those specific circumstances. This allows our brain to CREATE a pain experience, specifically tailored to how much it thinks it needs to protect us. Pain is our body’s in built alarm system, designed to keep us safe and draw our attention to potential danger – allowing us to remove ourselves from dangerous situations, or at the very least, take action such as bracing an area or calling our local Osteo! How amazing is that – our brain really does have our best interests at heart, bless it’s cotton socks.
The amazing-ness of our body doesn’t stop there.
If our brain is given context that seems dangerous – such as a person believing that their pain will prevent them from working, playing with their children or engaging with hobbies, the pain it creates will be worse. If the pain feels worse, we often feel scared because we believe that our injury must be severe. If we’re scared of what is maybe happening to our bodies, our brain feels further threatened, and our pain feels worse again. It’s a vicious cycle.
All this time, our brain is still comparing our context to the “danger” messages coming from the tissues. When pain persists and our brain feels threatened, it has the capacity to “ask” for more information from our tissues. Now, hold on here because it’s about to get a bit complicated.
We are constantly having information fed to our spinal cord from our tissues, which can in turn be send to the brain. Sometimes, this is just “noise” – signals that aren’t important enough or severe enough to be sent to the brain. We have nerves which come from our brain and travel down the spinal cord, whose job it is to inhibit this “noise” – to cancel it out and prevent it from travelling to the brain. If these signals never get to the brain, the brain doesn’t have to worry or do anything about them. These nerves are called descending modulatory systems, and they’re normally working quite a lot to cancel out the “noise” from our tissues.
When we injure ourselves, these pathways are still working, but will allow only the stronger, more important messages through to the nerve which relays to the brain.
When pain persists for a while, our brain can choose to dial these descending modulatory pathways right down, thus opening the floodgates for lots of “danger” messages to make their way to the brain, whether they be big and important or small and unimportant. This is because of what I mentioned above – if the brain’s context indicates threat, then it will “ask” for more information from the tissues by allowing more information to reach it.
The nerves themselves also contribute – when pain has persisted, the nerves become more sensitive. This means that they’re more likely to shoot a message up to brain than in times of no pain. I could do an anatomy lesson on how nerves talk to each other and how neurotransmitters work, but for simplicity’s sake, this means that the small, unimportant “danger” messages usually ignored by our nerves somewhat become available to our brain, when they’d normally just be cut off. Clever huh?
The annoying part is that perhaps the situation isn’t threatening. Perhaps the patient’s thoughts, previous experiences, emotions, stress, hormones, work situation etc, has convinced the brain that an injury is a really big deal, when really, the tissue damage is minimal. Unfortunately, our brain doesn’t, and can’t know this. It’s trying to act in our best interests given the information it has at hand.
So back to the point of this post – why do flare ups happen?
If we have been injured and have been in pain for a while, our nerves, spinal cord and brain WILL HAVE become sensitized to pain – it’s a normal, protective biological process. It DOES NOT mean that our tissues are terribly damaged, as discussed above, we can have severe pain but only minimal (or even no) tissue damage.
The sensitivity I discussed above has been shown to improve in response to exercise – by providing our nerves and spinal cord with “safe” information, we can assist in overriding the processes which cause sensitisation to happen.
Sometimes however, our brain may still have a hissy fit, and our sensitive nerves might become a bit overwhelmed. We might start lifting heavier weight – important for rehab, but unfamiliar to our bodies. This might “set off” danger messages, which our nerves and spinal cord relay to our brains because we’ve lost the filter that would normally weed them out. This absolutely can result in pain.
The key thing is that this pain is not representative of damage. We’re still doing the right thing by exercising as we are improving the sensitivity of our nerves – we can train them to be less sensitive.
In my next blog I’ll give some practical tips on managing flare ups, but until then, remember – they’re not an indication that you’ve further damaged yourself!
Until next time,