We all experience pain. It happens when we fall over as children and graze our knees, when we drink too much alcohol and give ourselves a hangover, or when we learn the hard way not to touch things that are hot. This kind of pain—acute pain—is part of life. The message is so clear and unambiguous that most of us don’t give it a second thought.
Through long experience, we’ve been conditioned to understand pain based on the simple formula that pain = problem. If pain is a problem, the quicker we can mask, dull, or remove it, the better. In other words, we conceive of pain as a simple cause-and-effect equation. “I feel pain, therefore something is wrong.” Sometimes that is the case. At other times, particularly in the case of chronic pain, it’s not that simple.
To understand the roots of chronic pain, and the reasons why it persists even when we treat the apparent “problem,” we must begin by changing our thinking about it. To change how we think about chronic pain, we must step back, outside of the constraints of existing healthcare delivery, to look independently at the science and to reexamine that science without the pull and biases of current methodologies, economic incentives, and educational and practice disciplines. In other words, we must look at the science independently and approach it in a way that will allow us to use it in crafting a better solution.
Where Does Pain Come From?
Where do you experience pain? If you hurt your hand, you feel pain in your hand. If you suffer food poisoning, you feel pain in your stomach. That much is obvious, right? Perhaps not.
Our latest scientific understanding of pain clearly illustrates that all pain originates in the brain. In fact, our tissues have no ability to feel pain; they only have receptors. These receptors gather information and transmit that information through the nervous system to the brain, which interprets it and generates a sensation or expression of that interpretation.
This may seem counterintuitive. If you put your hand on a hot stove, you will feel burning in your hand, not in your brain. If you leave your hand on the hot stove for a long time—not an experiment I recommend trying for yourself—you will see evidence of the burn in the flesh of your hand, not in your brain.
The only reason you feel the pain, however, is because you have a brain, not because you have a hand. In this case, as in the case of all acute pain, the pain experience is intended to protect you—to trigger you to take action (in this case, to pull your hand off of the hot stove as quickly as possible, to avoid doing more damage to the tissue). In the event that damage to the tissue has occurred, the pain will linger while the tissue heals and normalizes. Once it’s healed, the pain should go away. It is no longer necessary, no longer protective or productive. That’s acute pain.
The difference between acute pain and chronic pain is that chronic pain doesn’t go away. It may appear initially as the result of an injury or for some other reason, but it stays even when the ostensible reason for its existence has long since cleared up. When the protective function of pain is served, it should disappear. If it doesn’t, we’re in chronic pain territory.
Generally speaking, chronic pain is defined as pain that has been present longer than three to six months, which is typically enough time for tissue to have healed. Chronic pain can also include any pain that is growing disproportionately to its cause, or pain that arrives without a clear cause.
This experience has a top-down impact on the tissues and the body, which are reacting to an inappropriate expectation of pain generated by the brain. The brain sends a message to the tissues to expect pain; the tissues react to that expectation and create a physiological response in the tissue, such as inflammation, limited mobility, increased sensitivity, physiological changes to the nervous system, and so forth. These changes in the tissue create a heightened sensitivity, which then cause normal sensory and movement inputs to be falsely interpreted by the brain as “threats,” to which it responds by generating an expanded pain response.
This becomes a vicious cycle. The brain generates an expectation of pain, the tissues respond by creating the experience of pain, and the brain continues the cycle by intensifying the expectation. If we keep in mind that although the pain is felt in the body, the pain itself is really a product of the brain, we can begin to change our thinking around chronic pain and its treatments.
A Different Way to Address Chronic Pain
When we recognize that chronic pain stems from the brain, we can both understand the limitations of existing treatments and consider different methodologies to relieve it. Drugs may dull the sensation of pain, but they do nothing to alter the signals the brain sends to the tissues. Worse, they come with significant risks and side effects. Drugs may lead to addiction and additional health issues, dulling the pain but simultaneously dulling our ability to fully experience life.
To tackle chronic pain effectively, what we need is a way to convince the brain that there is no need to send “threat” signals. If we can do that successfully, it will stop conveying a message to the tissues that they need to create the experience of pain, and they will respond by ceasing to hurt.