All told, and as we know so well, living in constant pain is challenging and complex, as is pain itself.
Understanding the different types of pain is helpful as it leads to better care and a clearer path towards improved health. To begin, we know that…
“Pain is a message, a sort of public service announcement from your brain about a credible threat. Supposedly. That’s how pain arising from tissue damage — is supposed to work anyway….
“Pain is predictably unpredictable, thanks to our minds….(pain is) all under the total control of our brains…(which) have complicated and conflicting priorities for us that we are oblivious to. The result is…a somewhat paranoid guess about how much danger we’re in, and that’s when everything’s working correctly.” ~ Pain Science
We know that that there is a clear difference between acute and chronic pain. Acute pain is short-lived, relatively speaking, and does in fact come to an end. Chronic pain lasts more than 3 months (but, and as we well know, can last much, much longer than that). Acute pain is more easily described and observed and is usually associated with specific parts of the body. Chronic pain is much more subjective and not so readily observed or described.
We have to try though…
The Three Types of Pain
There are essentially two types of pain – nociceptive pain and neuropathic pain however nociceptive pain can be further categorized into two sub-categories, somatic and visceral. Of the then three types, neuropathic pain is the most complex. Noteably all three can manifest as either acute or chronic conditions.
1. Noiceptive Pain
For beginners nociceptors, or pain-detecting nerves, are nerves that send a message from an area of injury within the body, up through the spinal cord to our brains which then interpret the signal and react, “notifying” us with the message of pain. Their job, in essence then, is to get us up and doing something to address and repair the body. A good short video about nociceptive pain can be found here.
a. Somatic Pain
Somatic pain is caused by the activation of pain receptors found in our skin or the musculoskeletal tissues (including structures deep in your body such as joints, bones, tendons and muscles). It can be caused by an injury, heat or trauma (including surgery), excessive activity or activity that causes us to misuse our bodies (think weekend warriors for example) or inflammation. It is usually easy to locate and is frequently described as achy and/or dull although it can be experienced as quite intense. Headaches, tissue and sport’s injuries, osteoarthritis, bee stings and back pain (not caused by nerve damage) are all examples. Generally speaking, somatic pain is usually aggravated by activity and relieved by rest and NSAIDs.
Chronic pain is not often tied to this type of pain and the, what would seem to be, “dramatic” issue in our tissues.
“The evidence that tissue pathology does not explain chronic pain is overwhelming (e.g., in back pain, neck pain, and knee osteoarthritis).” ~ Lorimer Moseley
b. Visceral Pain
Visceral pain occurs when our internal organs are damaged or injured. Nociceptors in our internal organs- think stomach, bowels, and the urinary tract- are not as well supplied by sensory nerves and so the pain may feel dull, vague and diffuse, pressure-like and/or squeezing with other accompanying sensations including nausea, fever, and malaise. Visceral pain is often harder to pinpoint. Examples include menstrual cramps, gastrointestinal disorders including irritable bowel syndrome, tumors and cancer. Visceral pain is often treated with NSAIDs or opioids but, depending on the pain’s origin, treatments can obviously become much more complex.
Neuropathic pain is damage to the nerve fibers and nervous system itself, central or peripheral, including the spinal cord and the brain, either from disease, injury, or structural issues. Neuropathic pain is a big and complex category and difficult to remedy. It’s often experienced as stabbing and/or burning, stinging, shooting, and even includes the sensation of electrical shocks. Examples include sciatica, multiple sclerosis, post-shingles pain, diabetic neuropathy, and phantom limb pain. Neuropathic pain can be challenging to specifically locate and can come in waves of intensity and frequency. Unfortunately, as nerve cells do not heal well, it is the most likely to lead to chronic pain.
*As a footnote–
Fortunately these types of pain do not frequently overlap nor does “over-sensitivity” of the nerves (causing nociceptive pain to lead to neuropathic pain) occur. A great article by Paul Ingraham about this condition is here with note there of the tremendous resource and books out of University of South Australia’s Body in Mind.