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An Overview On Pain

Updated: Jun 9, 2022

An Overview On Pain: definition, causes, and treatments

Written by: Lisette Brown MPAS, BMedSc, LMT, Reiki Master/Teacher

June 2, 2022


What is Pain?

In 2018 the definition of pain by the IASP (International Association for the Study of Pain) was revised. It is described as “an unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage.”1 In addition to the revised definition, the IASP also noted other concepts, situations, and background that help understand pain and the fluid definition of pain.

  • “Pain is always a personal experience that is influenced to varying degrees by biological, psychological, and social factors.

  • Pain and nociception are different phenomena. Pain cannot be inferred solely from activity in sensory neurons.

  • Through their life experiences, individuals learn the concept of pain.

  • A person’s report of an experience as pain should be respected.

  • Although pain usually serves an adaptive role, it may have adverse effects on function and social and psychological well-being.

  • Verbal description is only one of several behaviors to express pain; inability to communicate does not negate the possibility that a human or a nonhuman animal experiences pain.”1

In general, pain is an uncomfortable feeling/sensation that signals the body that something may be wrong and may not be functioning correctly. Pain differs in duration, frequency, and intensity in every being. It may range from an annoyance to incapacitating. Pain descriptors that I have heard from my patients and clients include:

  • Steady

  • Tightness

  • Throbbing

  • Stabbing

  • Aching

  • Pinching

  • Heavy

  • Numb

  • Tingling

  • “Something is just not right”

In addition, pain can also bring about physical and emotional symptoms, such as:

  • Fatigue

  • Weakness

  • Lightheadedness

  • Nausea

  • Decreased/Increased appetite

  • Frustration

  • Anger

  • Depression

  • Anxiety

Pain is usually categorized as Acute vs Chronic.

What is Acute Pain?

Acute pain usually lasts seconds or minutes to hours, days, or weeks depending on the cause. It is associated with tissue damage, inflammation, which may be due to injury, surgery, or a brief illness.2

Acute pain is usually sudden, it’s a warning to your body that there’s an injury or disease affecting your tissues. Why do we need to feel pain anyway? The following is a basic description of your body’s response to pain called the withdrawal reflex.

  • Acute pain pathway activates when your body is introduced to a painful stimuli

  • Your body first responds with an involuntary reflex that does not involve the brain, it is an immediate reaction to protect your body

  • The signal then travels up to your spinal cord via neurons and finally to your brain, where you experience the sensation of PAIN!

  • Your brain then sends signals back down your spinal cord to your muscles that are involved in the pain pathway and you make voluntary movements to protect the area of concern

Acute pain protects your body from further injury, inflammation, or damage. When the tissue heals and the inflammation decreases, the pain should diminish. The word should appears because there are circumstances where the pain continues after healing has completed. In this scenario, pain, which was once protective, now serves no purpose and becomes chronic. When there’s no obvious explanation for the pain and it doesn’t go away on its own, it’s considered chronic pain. It may be temporary, or it may last indefinitely.3,4 (Image 1, Image 2)

Image 1. S. Oiseth, L. Jones, E. Maza. (2022, March 10). Pain: Types and Pathways.

Image 2. Lumen Biolife 101. Chapter 13-The Nervous SystemTop of FormBottom of Form. Reflexes.

What is Chronic Pain?

Chronic pain, in contrast to acute pain, worsens and intensifies over time and may persist for months, years, or throughout a lifetime. Chronic pain is most commonly caused by an initial injury that has damaged nerves and instead of pain resolving after the initial injury heals, the body continues in a pain cycle. It may also be caused by underlying health conditions, unfortunately, in some instances there is no known cause. The following are examples of causes for Chronic Pain:8

  • Cancer

  • Chronic Fatigue Syndrome

  • Complex Regional Pain Syndrome (CRPS), older term Reflex Sympathetic Dystrophy

  • Diabetes

  • Endometriosis (uterine lining that grows outside of the uterus causing pain)

  • Fibromyalgia


  • Interstitial Cystitis (chronic bladder pain)

  • Injury Pain (continues after tissue damage and inflammation have healed)

  • Low Back pain

  • Neck pain

  • Neurogenic (pain caused by nerve damage):

  • Osteoarthritis

  • Post-Surgical Pain (continues after damage of tissue and inflammation have healed)

  • Rheumatoid Arthritis (autoimmune disorder that affects joints)

  • Scar pain (surgical or injury)

  • TMJD (jaw clicking, popping, locking pain)8

There is no agreed upon length of time that defines chronic pain and currently there is no cure only treatments to manage the pain (keep at a stable level, which differs for each person), reduce pain, increase flexibility and joint mobility. It is no longer considered acute pain if pain persists after healing is apparent.

Do not wait until your pain worsens to the point of disability, before getting evaluated by your primary care provider/healthcare team. Besides the most common pharmacological treatments be open to try other modalities of treatment.2 There characteristics that can help differentiate acute pain vs chronic pain.2,5 (Image 3: Pain Pathway for Acute Pain vs Chronic Pain and Table 1) “Acute and chronic pain if not properly assessed can result in inadequate pain management outcomes and can negatively affect the physical, emotional, and psychosocial well-being of patients.”6

Image 3. C.E. Whitten, M. Donovan, Kristene Cristobal. (2005, The Permanente Journal). Treating chronic pain: new knowledge, more choices.

Table 1: Differences between acute and chronic pain

Physiological Change

Acute Pain

Chronic Pain

Vital Signs

May vary consistently with degree of pain severity

No or minimal change

Purpose of pain

​Useful, Protective

Inhibits function and not useful, Not Protective

Central Sensitization

Short term; improves with healing of injury

Remains present despite absence of ongoing injury

Neuropathic Pain

Increases likelihood of chronic pain when present in acute phase

Common etiology of chronic pain

Nociceptive Pain

Often found during acute pain state

Commonly presents with some neuropathic pain

Table 1. S. Oiseth, L. Jones, E. Maza. (2022, March 10). Pain: Types and Pathways.

Image 4 Chronic pain cycle. The Role of Physical Therapy in Chronic Pain Management.

Treatment of Pain?

Unfortunately, acute and, especially chronic pain may be so significant that it affects your daily activities, thus changing the way you live. Assessment is one of the most important factors in treating pain adequately. Chronic pain may be characterized by the same descriptors as discussed in the acute pain section, however, the difference being that chronic pain usually does not go away and it is constantly present throughout the day with changes in intensity. It also has a more neuropathic characteristic:2,9

  • Burning

  • Chronic tension

  • Cramping

  • Deep ache

  • Increased sensitivity to area of pain

  • May be local, but most commonly it is diffuse surrounding the area involved

  • Numbness

  • Shock sensations

  • Squeezing

  • Stiffness

  • Stinging

  • Throbbing

  • Tingling

Chronic pain is frustrating to those who suffer from it because of the intensity of the pain and the fact that the area of discomfort may change daily and be difficult to describe. It is also more commonly associated with a psychosocial element due to the chronicity of living with pain. Table 2 describes elements to consider in properly and effectively managing pain.

Table 2. Finnerup, M.D. (2019, June 20). Nonnarcotic Methods of Pain Management. Engl J Med 2019; 380:2440-2448.

There is a variety of ways to treat pain. I feel the best way to treat pain, which is also now becoming a guideline in medicine, is to “treat chronic pain using nonpharmaceutical, noninvasive interventions such as manual therapies, exercise, and biopsychosocial therapies. Recent data reflects rising costs for spinal surgeries, whereas manual therapy, exercise intervention, and biopsychosocial pain treatments continue to be poorly reimbursed (if at all), and are not always widely available.”11

Non-pharmacological options are often disregarded by healthcare providers, either due to the lack of studies or their lack of knowledge and comfort level recommending such treatments. These approaches may also be snubbed by the individual who is enduring the pain, due to lack of knowledge, recommendation, or the desire for a quick fix. There is research and studies available regarding majority of the treatments under the non-pharmacological heading below, especially on Physical Therapy, Occupational Therapy, Manual Therapy (including Massage Therapy, however, there still needs to more studies and a bigger study group for completeness. It is ever evolving.) These interventions can be very effective for alleviating pain alone or in conjunction with other modalities.

Non-pharmacological interventions may include:11,14

  • Aromatherapy

  • Exercise

  • Hydrotherapy (heat and cold compresses)

  • Massage Therapy (my favorite of course)

  • Meditation (movement meditation like Tai Chi, mindfulness meditation, mantra meditation)

  • Music therapy

  • Occupational Therapy

  • Pet Therapy

  • Physical Therapy

  • Psychotherapy or cognitive behavioral therapy

  • Reiki

  • Therapeutic touch

  • Yoga

Pharmacological treatments include (examples going from less potent to most potent):11,14

Over The Counter Pain Relievers


Non-steroidal Antiinflammatories (NSAIDs)

Tricyclic Antidepressants (TCAs)

Selective Serotonin Reuptake Inhibitors (SSRIs)


Topical Agents

Opioid Pain Relievers

Medical Procedures (less invasive to most invasive):11,14


Transcutaneous Electrical Stimulus (TENS)

Nerve Block


Image 6. N. Finnerup, M.D. (2019, June 20). Nonnarcotic Methods of Pain Management. Engl J Med 2019; 380:2440-2448.

How does massage fit into pain management?

Manual therapy, considered by the studies I have recently read include:

  • Soft-Tissue Massage

  • Stretching

  • Joint Mobilization

Your body is a complex organism with an intrinsic nervous system that includes pain response with multitude of pathways and neurons sending signals to your brain constantly. The following may be a little dense and very science based, however, I am fascinated by the research and how the body works, so I am placing this in for those that are interested. The body has 3 main categories of pain (see table 3 below):15,16

  • Nociceptive

  • Neuropathic

  • Nociplastic (Central sensitization)

It has been researched and suggested that chronic pain may be due to the body’s increased pressure pain sensitivity and an impaired descending pain control pathway, this is called our Conditioned Pain Modulation (CPM), it’s how we process pain. The studies report that some manual therapies are mediated by CPM and massage activates the descending pain inhibitory pathway, which would mean that Manual Therapists can have a direct effect on reducing pain, thus, assisting in pain control and management.15,16

The research showed that massage decreases blood cortisol levels in individuals with a variety of pain conditions. It reduces psychological distress: stress, anxiety. Plasma levels of β-endorphins, peptides that have an analgesic effect to morphine, were tested before and after connective tissue massage and it was observed that there was an increase in these peptides comparable to acupuncture and exercise, which indicates the treatments effect on the body’s descending pain inhibition.15,16

Further research is warranted, more detail of the different types of massage that are available: Deep Tissue, Connective Tissue, Thai, Muscle Activation Techniques. However, Manual therapy has proven subjectively and objectively, through patient’s/client’s and therapist’s accounts, to relieve pain, increase joint range of motion, and improve function for a variety of musculoskeletal pain conditions. Sometimes medicine is behind on what we already know works. At this time, I am satisfied with treating my patients/clients with massage therapy as long as I appreciate objective improvements with each assessment and my patients/clients observe reduction in pain and improvement in function. If it works, it works.

Thank you for reading and stopping by.

Table 3. A.Dance. (2020, January 20). The Unexpected Diversity of Pain: It comes in many types that each require specialized treatment, and scientists are learning to diagnose different varieties. Knowable Magazine.

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1. IASP. (2020, July 16). IASP Announces Revised Definition of Pain.

2. Advanced Pain Care. (2016, October 21). Waiting for Acute Pain to Go Away: How Long Is Too Long?.

4. C. Derderian, P. Tadi. (2021, November 12). Physiology, Withdrawal Response.

5. S. Oiseth, L. Jones, E. Maza. (2022, March 10). Pain: Types and Pathways.

6. Lumen Biolife 101. Chapter 13-The Nervous SystemTop of FormBottom of Form. Reflexes.

7. C.E. Whitten, M. Donovan, Kristene Cristobal. (2005, The Permanente Journal). Treating Chronic Pain: New Knowledge, More Choices.

8. Regina Fink, RN, PhD, AOCN. (2000, July). Pain Assessment: The cornerstone To Optimal Pain Management. Volume 13(3): 236-239.

9. Image 4 chronic pain cycle. The Role of Physical Therapy in Chronic Pain Management.

11. K. Maryniak, RNC-NIC, BN, MSN. (2013, September 12). Pain Assessment and Management.

12. N. Finnerup, M.D. (2019, June 20). Nonnarcotic Methods of Pain Management. Engl J Med 2019; 380:2440-2448.

13. Communications Staff. (2022, February 23). The Need for Biopsychosocial, Multimodal Approaches in Treatment of Chronic, Persistent Pain.

14. E. Cirino, medically reviewed by D. Weatherspoon, PhD, MSN. (2018, September 3). What Causes Chronic Pain?.

15. Andrew D. Vigotsky, and Ryan P. Bruhns. (2015, December 16). The Role of Descending Modulation in Manual Therapy and Its Analgesic Implications: A Narrative Review.

16. Ruth L Chimenti, Laura A Frey-Law, Kathleen A Sluka. (2018, April 16). A Mechanism-Based Approach to Physical Therapist Management of Pain.

17. A.Dance. (2020, January 20). The Unexpected Diversity of Pain: It comes in many types that each require specialized treatment, and scientists are learning to diagnose different varieties. Knowable Magazine.

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