Why Do We Feel Pain?

Most people recognize that pain as a physiological phenomenon is unpleasant but necessary for health. It is a necessary warning sign that our body has been injured in some way and that we should stop our current behavior. Without pain, we would put ourselves into unnecessary harm which could maim or kill us.

However, for people who live with chronic pain, the issue is much more complex, and there are no easy answers. For many chronic pain sufferers, their pain symptoms began with a verifiable injury or health condition like a strained back or surgery, but the pain continued long after the original condition has subsided. For these chronic pain sufferers, there is no reason why the pain should persist.

What Is Pain?

To the layperson, pain is merely an uncomfortable sensation that occurs when some bodily tissue like the skin or musculature is damaged. While this is true in general, there are many instances in which pain is not indicative of tissue damage.  Many people who are involved in physical trauma may not experience any feelings of pain until much later, and some people with amputated limbs may experience pain in tissue that does not actually exist.

Therefore, pain is much more complex than the activation of a nerve receptor and a transmission to the brain. While peripheral nerves may send an impulse to the brain that some change has taken place, the phenomenon of pain doesn’t arise in the nerve outside the brain. It isn’t until the brain interprets the signal that you actually sense pain. Pain is therefore a cognitive interpretation of neural stimuli, and it is only present once a variety of cognitive processes have been completed.

Pain can therefore be influenced by many mental states.  The intensity of pain symptoms may be strengthened if there is fear, cultural influences, or a profound belief that the pain is potent. Chronic pain patients may upregulate the intensity of pain because they are anxious about it and have had previous experiences with overwhelming pain.

Is Pain an Illusion

If pain is a mental state, then there is an argument to be made that it is illusory. If you define an illusion as something that has no basis in reality, then some types of pain are illusions. Take for example, phantom pain that some amputees experience. There is no skin, muscles or bones to be injured that could stimulate nociceptors in a missing limb, but these people do experience pain.

In some cases, a patient’s brain may reorganize itself so that it can experience pain more intensely or for longer periods of time. It is believed that amputees with phantom limb pain are inducing pain symptoms as a means of avoiding additional bodily harm; the brain interprets the missing limb as a danger and uses pain to prevent future harm.

In one pain study, human subjects were touched with a cold metal rod that was red or blue. Despite the metal rod being the same except for color, those touched by the red rod reported much more pain than those contacted by the blue rod. The study administrators concluded that perception plays a key role in how pain is interpreted.

How Is Chronic Pain Different from Acute Pain

Almost 20 percent of the adult population in the U.S. suffers from pain that lasts longer than three months, which qualifies it as chronic pain. This included conditions like lower back pain, arthritis or migraines. However, for most chronic pain sufferers, the pain they experience is quite different than what a person may feel due to a broken arm or the flu.

Acute pain may be just as intense as a chronic pain condition, but acute pain is related to an injury or illness.  Once the injury or illness is resolved, this kind of pain disappears. Acute pain is symptomatic of another health condition, while chronic pain may be a disease in itself. There are many aspects of chronic pain that distinguish it from acute pain:

  • Persistence—unlike acute pain which is transient in nature, a chronic pain condition persists for at least 3 to 6 months. While the pain does not have to persist continually during this period, it usually manifests more days than not.
  • Treatment resistant—chronic pain does not improve dramatically with therapies, although there may be minor improvement. Although this is, of course, dependent upon the therapy and the patient, most chronic conditions do not respond to conventional treatments.
  • Emotional component—the brain processes pain, anxiety and depression with almost the same neurochemical processes which is why most chronic pain sufferers also exhibit mental health conditions as well.  That is also why many chronic pain patients experience some improvement in pain symptoms once their anxiety and depression are also treated.
  • Pain is the disease—unlike acute pain that resolves once the underlying health condition disappears, many chronic pain conditions are illnesses in themselves. Although there is a physiological cause like overexcited nerves, the chronic pain is not a symptom but the condition. For many chronic pain conditions—like fibromyalgia or neuropathy—there is no known cause, but there is progress being made.

Is Pain Beneficial?

Most of us agree that pain is unpleasant and that the less of it, the better.  However, there are some strong arguments that some forms of pain do offer real benefits. In its most beneficial form, pain alerts us to damage to our bodies; people with congenital insensitivity to pain often fail to live long lives because they don’t have pain to alert them that their body is at risk.

This argument, however, is less applicable to chronic pain which is, in many cases, not related to an underlying health condition. The overwhelming medical consensus is that most kinds of chronic pain produce many health problems like stress, depression and insomnia without any health benefits. Pain has an important role in maintaining health, but when there is ongoing pain without a related cause, that usefulness diminishes to almost nothing.

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.