By Robert T. Cochran, Jr. M.D.
(Reprinted with the author's permission.)
What is Chronic Pain?
Pain is a universal human experience. We all know what it is like. Few of us, however, know enervating and debilitating chronic pain. What is it that distinguishes the disease chronic pain from the inevitable and sometimes incessant pain that we all endure? It is difficult to make a certain distinction. Unfortunately, there is as yet no adequate definition of the disease. The reasons for this are several, and they are worth exploring.
Chronic pain is a very protean illness. It has many faces. It may appear as fibromyalgia, back pain, tension headache, or any of the myriad other painful disorders. Thus, our attempt to define the illness is much like the proverbial blind men trying to describe the elephant. Each recognizes a part, none identify the whole. We can actually name the blind men. One is a rheumatologist who describes fibromyalgia. Another, an orthopedist, who describes a ruptured lumbar disc. A gynecologist describes chronic pelvic pain; a neurologist, tension headache; and a psychiatrist, depression. The list could be extended indefinitely. Every physician, specialist or generalist, encounters the syndrome of chronic pin. Each sees a piece of it. Few see the whole.
Let’s compare chronic pain with cancer and infectious disease, for these, too, are very protean illnesses. There are many types of cancer, and they behave quite differently. There are many types of infectious disease. Some are caused by viruses, others by bacteria, and yet others by fungi. According to the type of organism, infections will show enormous variability in their clinical behaviors. Nonetheless, we recognize that cancer and infection each represent a single core disease. We know this because we can see, under the microscope, the nature of the illness. We cannot, however, see the nature of painfulness under the microscope. There is as yet, nor will there likely be in the foreseeable future, a diagnostic test for pain. Nonetheless, there are ample reasons to presume that a state of chronic pain represents, like cancer and infection, a single core illness.
Most texts define chronic pain as that which persists beyond six months. That is certainly an inclusive and encompassing definition. Few would debate that pain of six months’ duration constitutes chronic pain. The time value, however, is highly arbitrary, almost to the point of meaninglessness. Surely the patient who suffers incessant pain should not have to wait six months before being accorded a diagnosis!
Let’s look at some specific examples. A muscular sprain or overuse injury usually resolves within a few days or weeks at the most. A more severe injury, such as occurs to the ligaments in an ankle sprain, may last several weeks or even a few months. Shingles usually lasts four to six weeks. A ruptured disc in the lumbar spine may cause persistent pain, but if the patient continues to hurt for anything approaching six months, surgery is warranted, and in that case recovery is usually achieved in a short while.
The time value of six months is much too long, but it is useful because it recognizes that almost any painful condition should resolve within a measurable time frame. This offers a new dimension to anticipated time of recovery. It begins when the patient should be getting better but isn’t. This is admittedly a very subjective definition. The lay person will be annoyed by its imprecision, but every physician knows exactly what I am talking about.
Let’s fast-forward to another idea, one which is the central theme of this book. Chronic pain, I will suggest, is the product of the mind, and it begins at that point in time when pain becomes a cerebral rather than a somatic experience. When pain persists longer than it should, beyond accountability, a variety of seemingly unrelated things happen, and they usually occur within a rather short interval. Appetite changes. Sleep becomes disordered and nonrestorative. Exhaustion and fatigue overwhelm. Memory is impaired, and the very act of thought disordered into persistent ruminations about pain. Mood is affected with fractiousness, irritability, and depression. All of these are a product of a mind in disarray, and they are the cardinal symptoms and identifiers of chronic pain. Now we can really get our teeth into a definition. Chronic pain is a state of pain characterized by destruction of the very architecture of fundamental existence. With that in mind, let’s look at a few examples of what is and what is not chronic pain.
The migraine headache can be extraordinarily painful. As every migraineur (one who suffers migraine) knows, it can be a devastating experience, attended by disordered sleep, loss of appetite, and sometimes profound changes in mood. These, certainly, are the symptoms of chronic pain, but in the migraineur they last but a few hours or a few days at the most. Migraine is a disease of intermittent painfulness. It is not chronic pain. That is a disorder of incessant painfulness (there are exceptions, but these will be addressed later).
Rheumatoid arthritis is an inflammatory disease of the joints. It is a crippling and sometimes even mutilating disease, and it can be very painful, but it is not chronic pain. Most rheumatoids live useful and effective lives. They do not want for sleep, appetite, or good humor.
Shingles can be a dreadful disease. It generates severe pain that lasts for weeks. During that interval, the patient experiences all the symptoms of chronic pain. Sleep is disordered with frequent painful awakenings. Appetite is diminished. Food loses its flavor. Emotions are disordered with irritability and despondency. The architecture of a useful and happy existence is destroyed. Does this mean that the patient with shingles suffers chronic pain? Perhaps, but probably not – because although he may lose sleep, energy, and appetite, he does not lose hope. He can be told that his painful experience will be self-limited and that with time he will get well. Compare with fibromyalgia and tension headache. Victims of those disorders cannot be told that they will spontaneously recover. It is the lack of hope, perhaps more than anything else, that defines chronic pain.
Shingles, destructive though it is, is not chronic pain, but it may evolve into that disorder. Just as a muscular sprain may evolve into fibromyalgia, and migraine into tension headache, shingles may lead into chronic pain in the form of post-herpetic neuralgia. Perhaps in no other illness can progression of acute into chronic pain be so demarcated. It occurs at that point in time when the infection is arrested and the rash disappears, but the pain continues – when the patient should be getting better but isn’t. This is also the point at which pain loses certain pathologic accountability. The nerves, so inflamed and dysfunctional during the acute interval, have regained their integrity. They show no abnormality to even the most discriminating tests of their structure and function, and yet they continue to generate a pain which will last a lifetime.
Let’s compare pain, as I will do often in this book, with other experiences. That of grief is a good place to start. With the loss of a loved one, we mourn. We are saddened and tearful, sleep-deprived, anxious, and subject to strange imaginings and often a sense of guilt. These, it bears emphasis, are expected, even normal behaviors (just as the pain of shingles is an expected and normal behavior). Grief, like most pain, is typically a self-limited experience. With time, it goes away. Occasionally it persists though, and when grief lasts longer than it should (and again we are forced to meet an uncertain time frame), the experience of sadness is no longer just grief. It is depression, and that is a disease. Grief may evolve into depression just as shingles may evolve into post-herpetic neuralgia. The analogy is more than apt.
Pain begins in the body with corporal injury, usually a random and accountable event. When it persists beyond accountability, it becomes a mind-dominant experience associated with a stunning variety of behavioral effects. These are the symptoms of chronic pain, and it is their study, quite as much as that of pain itself, that will allow us some understanding of the disease. It is quite difficult, most of the time, to say exactly when chronic pain begins. We have but modest understanding of exactly how it happens but we can see, with great clarity of vision if we but try, just why it happens.
For more information about the author and the book "Understanding Chronic Pain: A Doctor Talks to His Patients", please visit www.understandingpain.com