What Causes Pain, Triggers and Overlaps?

Causes, triggers and overlaps.

Margo McCaffery, Specialist Pain Nurse

Given the landscape of pain in the United States, as evidenced by the volume of new pharmaceuticals arriving on the market every day and in addition to our well-known epidemic of over-prescribed, over-used pain relief medications, we have a problem. 

The reality of pain is that, while every day bumps, scapes and bruises can be an inconvenience, recurring and nagging pain is quite often a symptom of a chronic condition or disease, and can even be the precursor of a fatal illness. It is a relentless communication between our brain and back to our bodies that something isn't right. Certain treatments relieve the discomfort, but where are we in our quest for what makes it go away, once and for all? Those who suffer pain day in and day out would say, we've not even stepped onto the bridge between wrecked bodies and well bodies. Pain is our only link. 

Whether acute and chronic discomfort is a sign of degenerative disease, autoimmune disorders, inflammatory conditions or GI ailments, members of our society contend with it every day of their lives. 

Chronic pain affects about 1 in 5 adults according to the Centers for Disease Control and Prevention (CDC). Nearly half of these people report that pain frequently limits their daily activities. 

The response of the scientific community has been ever more and more ludicrously named pharmaceuticals that are as ridiculously priced. When do we get to the heart of the matter? What is wrong with us?

With pain, our bodies are trying to tell us something. The type of pain is critical to decoding it's message.

There are four types of pain and your body expresses each in a different way. They can layer, and when they do, they can turn a life upside down in multiple ways. 

NOCICEPTIVE (/ nōsēˈseptiv/) PAIN is probably the most common and likely what a healthy child would complain of after falling down or getting hit in the face with a ball. It probably wouldn't cause great concern because the pain fades as the wound heals, sometimes as quickly as ice cream is introduced. In us elders, we might feel the sting a bit longer, we might bruise more easily, but these types of hurt are just that, hurt. This kind of pain is sort of the body's first responder to an issue that could cause it damage - the troops are nociceptors. Keep in mind that what they report is the state of the tissue they represent. The brain is what translates that into pain.

Nociceptors are receptors found all over the body whose purpose is to detect any type of potential tissue damage and report possible bodily harm to the brain. These receptors exist in nearly all animals, even those with simple nervous systems. Potentially harmed parts of the body include skin, muscles, bones or other tissues. Nociceptors can also detect the threat of chemical damage which happens when a body comes into contact with chemicals, and similarly thermal damage from extreme temperatures. 'Nociception' is the physical recognition of harm - it's the nociceptor communicating a threat to the brain which then causes us to jerk away from the cause or stop the activity. Think of accidentally touching the hot part of the curling iron or brain freeze after a big sip of a Slurpee. Nociceptors are right there on the front lines to tell your brain - "Make it stop!"  

Injuries that cause nociceptive pain include:

• bruises
• burns
• fractures
• pain caused by overuse or joint damage, such as arthritis or sprains

In the case of nociceptive pain, it usually goes away as the injury heals. If the pain continues, it's an indication of chronic damage.

The other main type of pain is Neuropathic, although there are  a couple of "sub-pains" - inflammatory and functional. These are not "sub" in that they are lesser, but in that they can be the amalgamated consequence of the major pain types. Some consider neuropathic, inflammatory and functional as "Boomer Pain," because they are indicative of the chronic conditions increasingly experienced by America's aging population. Think about arthritis and lower back pain: there are 66 million Americans with arthritis, and low-back pain disables 5 million people in the US and forces people to lose 93 million work days each year. If you're not a Boomer, but have experienced lower-back pain - you are not alone and we don't mean to leave you out. But the truth is that the younger you are the more likely you will recover from the twist, the fall or moving a couch than when you reach your 70s and 80s. 

What's important is that pain is now on the radar of health care professionals and there is a regulated spectrum of pain they have begun to take very seriously. With the 1-10 ranking of pain as perceived by patients, doctors are learning that they have to listen to us and take our experiences seriously. After so many have become addicted to the medications prescribed to ameliorate pain, we are also becoming more savvy as consumers, looking for root cause and organic solutions versus simply wiping out the signals our bodies are sending. 

NEUROPATHIC PAIN, unlike the relative "owie" of nociceptic pain, is caused by damage to the nervous system. If you have ever experienced something like "shooting pain," this is your nervous system sending messages to your brain and the "shooting" or "pulsing" sensation is likely caused by the abnormal way that it travels along the nerves. It might feel like a burning sensation. 

This type of pain is usually chronic, caused by progressive nerve disease or the result of injury or infection. Unlike nociceptic pain, neuropathic pain can flare up at any time without a precipitating event. The body will just send signals to the brain, unprompted. This type of pain tends to get worse over time. Causes of neuropathic pain include disease, infection, injury, and loss of limb. Even treatments for cancer, such as chemotherapy and radiation can impact the nervous system causing abnormal pain signals. Shingles and syphilis can cause this type of pain. In fact, when the loss of a limb results in some people claiming 'phantom limb syndrome,' or pain from a limb that isn't there - the brain is actually receiving faulty signals from nerves near the amputation site. 

Neuropathic pain is often the result of serious and possibly uncorrectable damage resulting in potentially persistent, agonizing pain. This is chronic pain. It is life-changing, and means you are sometimes unable to participate in daily activities, some as simple as putting on socks or getting into a car unassisted. 

INFLAMMATORY PAIN, not one of the main two, but of the top four types of pain, is the result of a system, inflammation, that is designed to protect and to heal the body. While infection stems from bacteria, a fungus, virus or parasite, the resulting inflammation is the body's response to that infection as it works to send extra white blood cells to the area to fight off the invaders. This increases blood flow to the area that can result in swelling, redness, and warmth. 

This kind of pain is no picnic either as it can have myriad hard-to-discover causes, which often fall into the category of autoimmune disease. This is inflammation caused by the body attacking nothing. It's an abnormal reaction to normal in that your system attacks itself when nothing is wrong. Sometimes this type of autoimmune reaction can be controlled by diet, as with ulcerative colitis or irritable bowel syndrome, but in the case of rheumatoid arthritis, little can be done except avoiding certain activities or managing the pain orally or topically. 

FUNCTIONAL PAIN, the last course in the pain picnic, is basically the diagnosis when nothing else can be determined. The condition will be named after the organ that is malfunctioning, such as musculoskeletal pain in fibromyalgia or visceral pain in irritable bowel syndrome. 

This image from painscience.com pretty much sums up the dynamic of pain, and how, after looking at the various types, they can compound, layer and overlap to put a victim into pain hell.

From nociceptic hurt, which can be prolonged depending upon the damage done, to chronic neuropathic agony as the result of untreated injury or even inherited tendency for a disease, each stage of pain threatens to bleed into the next. 

In the case of ongoing and life-altering pain, the solution in most instances is to ameliorate symptoms. Are pharmaceuticals the best remedy? Are there alternatives.This Boomer thinks so. Stay tuned for the next episode, where I'll look at the effects of pain on people, work, families, finances.