Last updated: Mon, Mar 10, 2025
This section covers what is usually called pain physiology. It looks at the mechanisms that are involved in creating the experience of pain. Much is known about these mechanisms, from the level of individual molecules up to the brain components that convert the state of the system's tiny components into human experience.
You don't need to know about these mechanics in order to suffer pain. You do need to know them to devise effective treatments or to understand why pains can be difficult or impossible to accurately diagnose. You need to know them in order to understand why researchers and care providers find it difficult to deal with pain suffering and pain sufferers. You need to know them in order to understand why pain can be difficult or impossible to effectively suppress. You need to know them to provide a framework to judge the effectiveness of your care providers. You need to know them in order to conduct your own search for ease.
At a political level, you need to know about the mechanics of pain in order to have an informed opinion about whether the medical and scientific resources employed on the problem are being used effectively. This is too important to leave to those who have economic and social stakes in the particulars of how pain is now treated.
An important insight is available to you. This is the awareness that there is a huge gap of understanding separating molecular messengers and cell components from the human experience of pain. When you know only the neural receptors involved, you really know nothing about pain experience. The quest for an understanding of pain can lead to a broader understanding of what it is to be a human.
Pain is always a feeling that conveys information about you to you. We all experience this, and we use the pain feelings to adjust our activities. For most people this is pretty much all you need to know about pain. The system works pretty well for most of us most of the time.
But the fact that you're reading this suggests that you may benefit from knowing more. If you are a pain care provider, you've already devoted a great deal of time and effort to this, to enable yourself to be helpful. If you are a pain sufferer, I can suggest three reasons why knowing more about how the pain system works will help.
(1) If you know nothing of the inner workings of your pain system, anything seems possible. Though this might sound like a good thing, it leaves you with no basis on which to make decisions involving your pain. Should you follow your friends' advice? ("You need some new shoes.") Advice from the Web? Is your professional caregiver leading you in a promising direction? At any given moment, should you listen to the urgings of your pain or to your caregiver's prescriptions? (They will differ.) How much of your time, energy, and money is your pain problem worth? Questions of this nature, big and small, tactical and strategic, present themselves to you, and you're the decider. Knowledge of how the pain system works can also set limits to your dark imaginings during a long dark night.
(2) The information you get from your caregivers is likely to be partial and confusing. Many pain care providers, especially medical doctors, are focused first on gathering data to make a diagnosis, second on choosing a treatment strategy, and only after that on explaining what it is they think you should know. This is no different for pain problems than for a sore throat or any of a myriad of problems that care providers deal with. It's enough if the treatment is effective. I assume that your pain hasn't resolved, however. If the first treatment strategy doesn't resolve your problem, you are already in the business of making decisions about your care: Should you return to this doctor? When? Is it too soon? What should you be prepared to tell the doctor when you do return? I've found some doctors to be good at accepting and responding to questions, but always in a hurry. I've found that physical therapists and massage therapists are more forthcoming, in part because you have much more time with them. If you understand more about your own pain system, it will be easier for you to understand your care providers' pronouncements, easier to avoid misunderstanding them, and easier for you to help them understand your input.
(3) The world is full of contradictory ideas about pain. You will get different advice from different professional care providers, especially depending on the provider's field. If your pain problem is severe enough to be noticed, you will get advice and perhaps judgmental feedback from a lot of directions. Each recommendation, each reaction, is based on a theory of pain. Knowledge of how the pain system works will help you know what to take seriously and what not to.
If you are not a pain sufferer, but live within the world of one, especially if you are close or if you are the patient's advocate (if you attend medical visits with them), there is a special reason for you to be educated about pain. What you believe about pain is likely to be based on your experience with garden-variety pain. Chronic pain is different from normal healthy pain. Understanding the mechanisms of pain will make it easier for you to be helpful to the person you are helping.
Understanding the mechanisms and behavior of pain can occupy entire lifetimes, but a basic outline of the systems needn't be complex. I've included four separate sections about how the pain system works. The first section is a general overview. It describes the nervous system (the brain, spine, and nerves), and how they generate pain. It also describes some of the varieties of pain as they are distinguished by scientists and doctors. I describe some conditions that often accompany pain, such as sleep disturbance, but are considered to be separate conditions in the medical community. Finally in this section I describe what types of pain are most common and how common they are.
The later three sections about the pain system go into more detail to explain some of the ways that chronic pain differs from garden-variety pain, and why pain can be hard to understand and diagnose. The second section (Pain Science 2: Nociceptors and the Spine) looks at the way your spine is involved in generating and regulating pain. The third section (Pain Science 3: Neuroscience and the Brain) looks at the roles of the brain. The fourth (Pain Science 4: Partner Systems) examines how pain and your autonomic nervous system interact.
All four sections look at pain from the viewpoint of physiology, what we know about the structures and mechanisms that create the experience that we call pain. Just an overview of pain physiology reveals that pain can be mysterious and difficult to diagnose and treat.
The remainder of this book, then, is about other ways of looking at pain: where the ideas come from, how they function, and what difference they may make in your life. For an introduction to these ideas, see The Psychology of Pain.
Within this section...
Pain Science 1: Basics (Last updated: Tue, Jan 14, 2025)
Pain Science 2: Nociceptors and the Spine (Last updated: Thu, Nov 21, 2024)
Pain Science 3: Neuroscience and the Brain (Last updated: Fri, Mar 7, 2025)
Pain Science 4: Partner Systems (Last updated: Fri, Mar 21, 2025)
Pain Measurement (Last updated: Sun, Jul 28, 2024)
Pain Research (Last updated: Fri, Feb 21, 2025)
Or skip to...
The Psychology of Pain (Last updated: Mon, Nov 18, 2024)