February 22, 2009
by Ylisabyth (Libby) Bradshaw, D.O., M.S.,FACEP, Academic Director of the Pain Research, Education and Policy program at Tufts University School of Medicine
Does it matter whether pain is a disease or a symptom?
For people living and suffering with pain, such a question may seem irrelevant. Perhaps like splitting hairs.
“Just make the pain better.”
“I don’t care what category you put it in!”
“Don’t just talk about it. Do something! Anything to relieve this agony.”
Why would it matter whether and how medical professionals want to categorize pain?
Symptoms are defined as subjective experience; diseases are defined in objective terms, with specified causes, or associated signs and symptoms.
People with pain certainly have a personal, internal experience of pain. And, aside from asking a person to describe and rank the intensity of their own pain, there’s no medical test for determining the type of pain or its severity.
The predominant medical view for centuries has been that pain is a symptom, and viewed as an entirely subjective experience by an individual. Physiologically, pain has been seen as simply the transmission through nerves of information about damage or potential damage to parts of the body.
After all, when pain is caused by something inside the body – a ruptured disk, nerve disease, or compression from an expanding tumor – it seems that something is irritating or pressing on a nerve, which is then communicated, allowing us to feel pain. Pain is a classic symptom, it would seem.
And pain could hardly be expected to be a disease when it’s caused by forces from outside the body – a fall, an automobile crash, or even surgery; it seems completely straightforward – and easy to understand when nerves are compressed, crushed, or cut – pain is the symptom.
Yet, accumulating evidence in neuroscience says pain is more complicated. No matter what initiates pain – from traumatic forces to specific neurological disorders – if conditions continue, and the pain signal is maintained, specific bodily changes occur.
Measurable now in research labs, such characteristic, physiological alterations, arising from actively transmitting information about pain, can unfortunately become sustained biochemical changes. Ordinarily, our bodies reverse this process when the initial circumstances causing pain are relieved. Yet, too often these changes become irreversible, and permanent, resulting in chronic pain.
Two imperfect examples from our material world – Once cement is mixed and sets up, it becomes a new substance. Once glue is used, it can bind to a substance, and be impossible to remove. The science of pain is still discovering answers, and resolving uncertainties. OK, our brains and nerves are not comparable to cement, glue, or jello. Yet it is clear, signals about definite or potential tissue injury turn on many biochemical processes that transmit information about pain through our nerves. Over time, these can become irreversible changes. Pain, then, is beyond being merely a symptom.
Please join this initial discussion on the Pain Research, Education and Policy blog at Tufts University School of Medicine, and include your thoughts regarding, “Is pain a symptom or a disease?”
If pain is more than a symptom, does that make it a disease?
Common definitions of “disease” include impaired functioning*. From your knowledge and experience, how do pain conditions have impaired functioning?
We look forward to interesting exchanges from students, faculty, practitioners, alumni and members of the general public committed to improving the conditions treatment and prevention of individuals across all ages with acute and chronic pain problems.
* Disease -
“a condition of the living animal …[or one of its parts] that impairs normal functioning and is typically manifested by distinguishing signs and symptoms” MeriamWebster
“an impairment of the normal state of the living animal … or one of its parts that interrupts or modifies the performance of the vital functions, [and] is typically manifested by distinguishing signs and symptoms…” Medline