Pain is one of the most common reasons to visit a family doctor and treating pain effectively and safely is one of the most complex and challenging problems that we face. We may have recommended that you read this so that you can help us accurately diagnose and treat your pain. Perhaps this two-part article will help explain our thinking when we try to help patients with their pain. We will start by describing different types of pain. As you read, please think about what type of pain that you have been experiencing.
First, pain can be acute or chronic. Acute pain usually comes on suddenly and is caused by something specific. It is often sharp in quality and we all recognize common causes such as breaking a bone, or suffering a burn or a cut. Other causes include dental infections, labour and childbirth, or the after effects of a surgery. Acute pain usually does not last longer than three months and we are pretty good at helping people with this type of pain, with medications, braces, casts and medical procedures. Acute pain will usually gradually improve as tissues heal.
If your pain has lasted more than three months you may have developed chronic pain. I like this definition of chronic pain from Healthlink BC: “Pain is your body's way of telling you that something is wrong. It's normal for you to have pain when you are injured or ill. But pain that lasts for weeks, months, or years is not normal.” A writer in the New York Times put it very well several years ago: “...chronic pain often outlasts the original illness or injury, causing changes in the nervous system that worsen over time. Doctors often cannot find an underlying cause because there isn’t one. Chronic pain becomes its own disease.” Another excellent description of chronic pain can be found in this five minute youtube video from Australia. Treating chronic pain can be much more complicated and challenging than treating acute pain.
Before we focus on the treatment of pain in more detail, let’s review other ways of classifying pain. It is often really helpful for us to discriminate between nociceptive and neuropathic pain. Nociceptive pain is a medical term used to describe the pain from physical damage or potential damage to the body. Nociceptive pain often has structural causes such as a deteriorating disc in the back, or arthritis in the hip. It can also be caused by inflammatory disorders such as rheumatoid arthritis or by conditions that lead to poor blood flow to the tissues. We are often most successful at helping with this type of pain when we target treatment toward the underlying cause for pain.
Neuropathic pain is unpleasant and it can be shooting, stabbing or “electric shock like.” It can also come on in response to things that don’t usually cause pain such as cold or gentle brushing against the skin or when light pressure is applied. When this happens it is called allodynia. Neuropathic pain can result after damage to, or dysfunction of the nervous system but it can also happen when pain centers in our brains receive the wrong signals from the nerve fibers. Over time nerves and parts of our central nervous system can change and pain can continue long after healing has occurred. Tissues often look normal and it can be hard to tell how much pain someone is in when they have this type of pain. Unfortunately neuropathic pain can lead to troubles with sleep and emotional distress. Examples of nerve pain include carpal tunnel syndrome or sciatica which usually respond well to treatment. Other, harder to cure examples of neuropathic pain include diabetic neuropathy and complex regional pain syndrome.
Now that we have reviewed these types of pain, you should be able to help us identify which type of pain you are experiencing, using some examples:
Acute nociceptive pain: a broken bone requiring a cast
Chronic nociceptive pain: an arthritic hip that needs to be replaced by a surgeon and that has been worsening over the last twelve months.
Acute neuropathic pain: sciatica as the result of a herniated disc in your back starting two weeks ago.
Chronic neuropathic pain: longstanding burning pain in the feet caused by diabetic neuropathy.
Defining your pain accurately is very important in providing you with the best treatment. For example, many of the treatments for acute nociceptive pain are not helpful for chronic neuropathic pain and, in fact they can make things worse with side effects, dependency and even worsening of pain. It is also true that some medications and treatments that are prescribed to treat chronic neuropathic pain aren’t the best option for patients with acute nociceptive pain. Unfortunately, sometimes one type of pain can evolve into another, especially if it has been present for a long time and medication that was once helpful may need to be stopped or replaced.
Let’s focus briefly on how chronic pain of any type can evolve into chronic pain syndrome, a particularly challenging form of pain to manage. I like this definition from the Institute for Chronic Pain: “The vicious cycles of pain become clear. Chronic pain causes stressful problems, which, in turn, cause stress that makes the pain worse. This combination of chronic pain and the resultant problems that make pain worse is what we call a chronic pain syndrome.”
Healthlink BC also puts it nicely: “Regardless of the cause, chronic pain syndrome affects all aspects of your life, straining relationships and making it difficult to keep up with work and home responsibilities. Common reactions to chronic pain over time include fear, frustration, anger, depression, and anxiety. These feelings can make it harder to manage chronic pain, especially if you use alcohol or drugs to deal with your symptoms.”
We will talk more in part two about how we can help with chronic pain syndrome.
In closing, we’ll leave you with this image that one of our physicians likes: “Pain is like a layer cake.” The layers can include sleep, mood, amount of physical exercise, health of relationships with loved ones, among others. Asking about these layers is important, and sometimes, when we ask about them, it may seem like we’re not addressing your pain directly. We want you to know that we don’t think that your pain is “all in your head.” All of us have had patients protest when we have focused on other aspects of their lives in trying to better understand their pain. When you are in pain, especially when it has lasted for a long time, it can be really helpful for us to know a little more about the “layers in the cake.”
Now that we have reviewed some common definitions and terms in managing pain, we can move on to part two of this article (coming soon) that will review treatments for pain.
For those patients who want to read more on this topic, here are some good resources:
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