"The pain must be in your head." Have you ever heard that? The implication, of course, is that you're somehow making up your pain. But can pain really be "all in your head"?
The surprising answer is that all pain is in your head. Even when you get kicked in the shin, the pain exists only in your head, not in your shin
How does that work?
Well it turns out that pain is a brain output, rather than being something that the tissues input to the brain. Your brain takes in various inputs and it will feel pain if it interprets these inputs as representing tissues being damaged or being at risk of being damaged.
So what does this mean for how we think about pain?
It's easiest to think about pain in a purely pathological sense. You're in pain because you've sprained ligament Y or strained muscle X. A lot of the time this system works fine. But what it doesn't account for are the instances where there is no such explanation for someones pain, or for people who have injuries such as rotator cuff tears without any shoulder pain.
Thinking about pain as a brain output helps to explain these types of situations. Because pain is a brain output, it can be influenced by other things going on in the brain, as well as the input it is receiving from the tissues. These things going on in the brain that may positively or negatively impact on your pain include (but aren't limited to) your prior experiences with injuries, you family and cultural beliefs about pain, your mood, stress, depression, anxiety, your social inclusion, your work environment etc.
There is a spectrum where some people's pain is driven entirely by some pathological process, some people's pain is driven entirely from subconscious processes in the brain (like those listed above), and most people's pain is from some combination of the two.
How do we treat it?
There are a few things physios can look for to assess if there is a central component to your pain (that is, if it seems to be driven to some degree by processes in the brain). These include heightened sensitivity to light touch, and a non-mechanical presentation to the pain.
Centrally-driven pain can be managed and improved with things such as education, gradual increased exposure to exercise and a series of exercises called Graded Motor Imagery.
The take home message from this is this: If you or someone you know has been told that "the pain is all in your head," then that does not mean that your pain is somehow "made up." Rather, it's possible your pain may be contributed to by subconscious processes in your pain. So don't give up on your pain because it is something that can be managed.