Chronic Pain Vs. Acute Pain

If you have lived any appreciable amount of time, then you have experienced pain. Whether it results from merely stubbing your toe or it is the almost unbearable agony of cancer, you know pain is something you want to avoid. In its simplest form, pain is a biological signal indicating that harm has occurred to the body, but pain can be much more complex than this.

The most common type of pain is acute. This kind of pain may result from an injury or illness and lasts only as long as the condition.  Once healed, the injury no longer signals through pain that there is a condition that requires attention.  In most cases, acute pain may be uncomfortable, but it isn’t a serious health concern in itself.

On the other hand, chronic pain is pain that persists for six months or longer and has no obvious cause. In many cases, chronic pain may begin as acute pain related to an injury or disease but may continue long after the underlying health condition has been resolved. Among the most common types of chronic pain are

  • Lower back pain
  • Headaches
  • Arthritis
  • Fibromyalgia
  • Multiple sclerosis
  • Neuropathy

A Basic Understanding of Pain

You have experienced pain throughout your life, but you probably don’t understand the basic, biological mechanism that produces it. It may appear to be a simple signal from a pain receptor to your brain, but there is considerably more complexity involved.

Pain usually starts with stimulation of certain nerves. The most common stimuli include cuts or impacts but may also arise from joint pain, headaches or muscle injuries. These peripheral nerve cells generate a pain impulse using electrical currents and chemical interactions. The exact nature of the impulse depends on the type of stimuli.

This pain impulse is transmitted to nerves in the spinal cord.  The spinal cord acts like a sorting center, prioritizing certain impulses like a severe burn and relaying less urgent sensations more slowly to the brain.

Once the pain impulse reaches the brain, it is once again sorted, this time in the thalamus. The thalamus interprets the sensation and transmits it to the appropriate place in the brain. Signals may be sent to the frontal cortex for cognitive responses, limbic system for emotional responses or the somatosensory cortex for physical sensation processing. Your brain then formulates a response and then sends new impulses back to the injured area.  This may include increasing blood flow, initiating an immune system response, or moving a damaged limb. In many circumstances, your involuntary responses may precede your volitional reactions.

How Pain Can Be Modified

Although you may think that you instantly sense pain, the truth is that there is an involved journey for any pain sensation.  Along this pathway, your pain impulse may be changed in many ways.  For example, a pain sensation may be modified in the dorsal horn of the spinal cord, which acts as a gateway for nerve impulses.

There is a theory about pain that suggests pain impulses must pass through gates. The gate theory states that pain may be amplified, diminished or blocked at these gates. A common example of this mechanism in action is the absence of pain during combat or physical activity; the central nervous system ignores pain sensations in order to focus on higher priority neural activity.

The Problem with Chronic Pain

In most people, pain is a relatively rare occurrence and is therefore properly modulated. You experience an injury, followed by an intense burst of pain which gradually dissipates as the damaged tissue heals. If the tissue remains damaged, the pain may continue, and if it persists longer than six months, it is classified as chronic pain.

Unlike acute pain which disappears as the illness or injury is resolved, chronic pain may remain long afterwards. In some cases, this lingering pain may even intensify over time. Even more problematic is that in many chronic pain patients, there is no identifiable cause for the pain symptoms.

There are many potential causes of chronic pain that are currently under investigation, including

  • Pain receptors may become overly sensitive to stimuli
  • Neural networks can be reorganized
  • The central nervous system may fail to modulate pain impulses
  • Inflammation may over-stimulate pain receptors
  • Injury to nerves may induce dysfunction

Chronic pain can therefore be extremely difficult to treat. Depending on the person, chronic pain can be processed in many different ways. In some people, pain impulses produce an oversized reaction in the emotional processing center of the brain known as the limbic system. This can induce stress, anxiety and depression which can make pain symptoms more potent.

In many circumstances, it is not only important to treat the underlying physiological problem and the primary pain symptoms, but long-term chronic pain patients also usually compound their pain with secondary emotional issues that also need resolution. That is why many pain specialists recommend that chronic pain patients also participate in psychotherapy.

More physicians are encouraging their chronic pain patients to use mindful meditation or biofeedback. Mindful meditation enables practitioners to embrace all of the sensations that the body encounters, including pain. This not only helps patients control pain symptoms, but it also relieves much of the stress and depression associated with chronic pain. Biofeedback techniques also empower patients to manage their responses to pain via a pulse monitor or functional MRI.

There are many strategies to manage chronic pain, but for most patients, it usually involves multiple techniques applied simultaneously.

  • Regular exercise
  • Specialized diet
  • Mindful meditation
  • Elimination of harmful habits like smoking and drinking
  • Achieving a healthy weight
  • Psychotherapy
  • Biofeedback techniques
  • Removal of sources of stress
  • Participation in a support group
  • Pain medications
  • Corrective surgery
  • Transcutaneous Electrical Nerve Stimulation (TENS) or commercial versions like Quell
  • Physical therapy

It can be difficult to determine which chronic pain treatment is effective for you, so you should maintain a pain journal as you try new therapies.  You should also do so in close consultation with a physician or pain medicine specialist. 

Article written by: Dr. Robert Moghim – CEO/Founder Colorado Pain Care

M.D. Disclaimer: The views expressed in this article are the personal views of Robert Moghim, M.D. and do not necessarily represent and are not intended to represent the views of the company or its employees.  The information contained in this article does not constitute medical advice, nor does reading or accessing this information create a patient-provider relationship.  Comments that you post will be shared with all visitors to this page. The comment feature is not governed by HIPAA and you should not post any of your private health information.