The Causes and Affects Of Pain

Aspirin Alternatives: The Top Natural Pain-Relieving Analgesics, June, 1999

What is pain? Dorland's Medical Dictionary states that pain is "a feeling of distress, suffering, or agony, caused by stimulation of specialized nerve endings." A very clinical way of stating that our bodies have an incredible system available to us, using a "pain sensation" to signal us when damage is occurring. This is an important concept because many diseases and afflictions of the body cause pain.

The primary purpose of pain is its function as a protective mechanism for the body. It is part of the body's warning system. Pain usually is an indication that tissues have been irritated or damaged. For example, you may have burned yourself or sprained your ankle. However, there are times that pain can arise when there is no apparent damage or injury to the body.

Pain is an amazingly complex subject. First off, pain is an unpleasant "sensation" that we experience. The "pain experience" occurs in a number of ways and has many aspects to it. These include such things as a person's anticipation of pain, pain expectation, previous pain experience, emotional and psychological factors, cultural differences, the individual's tolerances and capacity to deal with the pain, etc. Pain is very subjective and individually based. What one person may experience as moderate or even excruciating pain, another person may experience as a mild pain and discomfort. This is an extreme example, but I have been amazed at the individual differences and tolerances I have witnessed in patients in my practice. It is important to understand that pain is not always what appears on the surface.

To provide you with a basic understanding of pain, we must begin with a brief discussion of the pain pathways in our body. While this material may seem difficult to understand without a medical background, a basic understanding of how our body stimulates, derives and interprets pain is very important.

The pain pathways discussed below are only one physical aspect of the complex experience that we call pain. I have made every effort to take this established clinical knowledge and put it into understandable terms; however, some words and statements don't lend themselves to simple terms.

To understand the pain pathways, we must have a basic understanding of the nervous system and how it functions. According to Dorland's Medical Dictionary, the nervous system is "the organ system which, along with the endocrine system, correlates the adjustments and reactions of the organism to its internal and external environment, comprising the central and peripheral nervous systems." In simple terms, the nervous system provides most of the control functions for the body; including both sensory and motor functions, as it responds and reacts to the environment outside and inside of us. For the purposes of this book, we will focus on those portions of the nervous system that relate to the experience of pain.

To best describe how our bodies come to respond to a "pain" stimulus, we begin with the pain receptors. Pain receptors are specialized sensory nerve endings that responds to various stimuli (such as a burning candle) by responding with a pain signal. Think of a piece of thread (the free nerve ending/receptor) that is lying in the skin or within a muscle. These "receptors" are spread throughout our skin, organs, bone coverings, arterial walls, joint surfaces, muscles and ligaments, etc.

When something occurs, such as trauma or damage, a signal is relayed to these specialized receptors that is interpreted as a "pain stimulus." At this point, the pain stimulus is transmitted along specialized sensory nerves to the spinal cord and up to the brain, where the pain stimulus is processed and a response is provided back to the various structures which need to initiate an action (such as moving our hand away from the flame).

The following is an example of the pain response process. The following scenario will provide you with an understanding of this process: You are walking barefooted and step on a nail. The 'negative stimulus" is the nail penetrating the skin of your foot.

1. The "pain receptors" in the skin of your foot are activated by the penetrating nail. This stimulation is translated into a "pain signal" which travels through the afferent (sensory) pathway to the spinal cord.

2. Within the spinal cord, the pain signal is sent through more sensory tracts to the brain, which becomes aware and analyzes the pain stimulus.

3. The brain then sends an outgoing signal to various areas of the body which initiates a response. The head, neck, arms, trunk and opposite leg (causing muscular reactive movements), and the tongue, throat and respiration (gasp of pain or an exclamation), all may respond.

4. Further, a signal is sent back down the spinal cord and out the "efferent" (motor) pathway to the "effectors" (motor receptors in the muscles); in this case, to the muscles of the leg and foot which stepped on the nail.

5. The final reaction is the sharp withdrawal of the foot from the nail (the pain stimulus).