What Is Chronic Pain?

Chronic pain is one of the most difficult clinical problems physicians face and can be devastating for patients. Learn more.
What Is Chronic Pain?
Paula Villasante

Written and verified by la psicóloga Paula Villasante.

Last update: 30 May, 2023

Chronic pain is one of the most difficult clinical problems physicians face and can be devastating for patients. Keep reading to learn more.

What is it?

This type of pain can’t be explained on the basis of somatic or neuropathic processes. It’s due to physiological alterations in pain transmission or descending pain modulating pathways. In any individual, central pain amplification can complicate neuropathic pain (1).

chronic neck cervical pain

Neuropathic pain syndromes develop after an injury or illness that affects the somatosensory nervous system. Therefore, neuropathic pain is defined as maladaptive pain that results from damage to the nervous system (3).

The ability to experience pain has a protective function. It warns us of impending or actual tissue damage and elicits coordinated reflex and behavioral responses to keep such damage to a minimum.

If tissue damage is unavoidable, a set of excitability changes in the central and peripheral nervous system establish profound but reversible pain hypersensitivity in the inflamed and surrounding tissue.

This process helps to repair the wound because any contact with the damaged part is avoided until healing. In contrast, persistent pain syndromes don’t offer biological benefits and cause suffering and distress.

Chronic pain affects the physical and psychological health of the sufferer. It has repercussions on daily activities, autonomy, employment, and economic well-being (6, 7).


This type of pain affects more than 1.5 billion people worldwide (4). An epidemiological study carried out in 1998 detected that 29.6% of the non-hospitalized Spanish population suffers from some type of pain, with 17.6% being chronic pain (5).

The epidemiology of chronic pain.

In 2001, Drs. Casals and Samper conducted a study involving 907 patients with up to 100 pain units in Spain.

The ITACA study (Impact of Analgesic Treatment on Quality of Life in Algias) attempts to describe and analyze the epidemiological and clinical characteristics and the quality of life of patients with non-neuropathic non-cancer chronic pain, most of whom are women (66 % women and 34% men, about 57 years old on average).

They concluded that the diseases with more intensity of pain were osteoarthrosis, osteoporosis with vertebral compression, and osteoarthritis. All of this was more related to the female sex than to the male sex.

Arthosis is the most prevalent osteoarticular disease in the world. The four most common symptoms or warning signs of arthritis that appear in the joints or in the area around them are as follows:

  • Pain
  • Rigidity
  • Difficulty moving a joint
  • Swelling

Osteoporosis is a bone disease in which there’s a decrease in bone mass density.

At the same time, osteoarthritis is a disease in which cartilage is damaged. When this happens, the bones rub against each other and this can cause pain, swelling, and loss of joint movement.


If within chronic pain, we exclude cancer patients and neuropathic pain, including headaches, there remains a group of patients with their own characteristics. The main cause of pain in these patients is osteoarticular and musculoskeletal degenerative or inflammatory disease.

Some related syndromes include the following:

  • Chronic headaches
  • Temporomandibular disorder
  • Fibromyalgia
  • Irritable bowel syndrome (IBS)
  • Interstitial cystitis / irritable bladder
  • Pelvic pain

It happens that these syndromes can be grouped together in the same individual. Many times, they increase and decrease over time with one or the other being dominant at a given moment.

For example, let’s say a patient has visceral pain. IBS may dominate the overall symptom profile for a time. Afterward, it may regress as fibromyalgia symptoms increase.

Chronic pain is also grouped with other somatic symptoms. Some of them are the following:

Therefore, several studies have shown that in patients with fibromyalgia, there can be alterations in sleep and cognitive function. For this reason, multiple diagnoses and multiple providers frequently occur in the same patient.


Genetic risk and environmental triggers

An individual’s risk of developing chronic pain could be predicted by a personal or family history of chronic pain. Huge advances have been made in understanding the genetics of pain. Sensitivity to pain is genetic. It differs in inbred rats and mice and runs strongly in human families (9).

Furthermore, it seems clear that environmental triggers and various experiences can be causes of chronic pain. In many longitudinal studies, chronic pain and other somatic symptoms can be predicted by child abuse and other trauma. Also due to a low educational level, as well as social isolation, depression, and anxiety (10).

Stress, arousal, and chronic pain

The development of chronic pain is associated with stressful events and symptoms often rise and fall depending on perceived stress.

For this reason, many studies have been conducted focusing on stress and stress response systems in patients with these syndromes. All these studies have obtained highly varied results due to the difficulty of defining phenotypes and comorbidities that can influence physiology and the stress-arousal system (1).


Self-regulation in chronic pain

Illness behaviors are often claimed to accompany chronic pain. Successful adaptation to chronic pain conditions may depend on an individual’s ability to self-regulate.

That is, the patient’s ability to control or guide and alter reactions and behaviors. The capacity for self-regulation varies depending on the person and the situation (11).

Chronic pain treatment

When pain becomes chronic, the goal of medical care becomes management, not the elimination of pain. Therefore, the institutionalized approach to eliminating pain is concomitant with the increase in the use of opioids for chronic pain not related to cancer (12).

Strategies for treating chronic pain include antidepressants that increase synaptic norepinephrine and serotonin, two agents that reduce neuronal excitability, and pain relievers.

A pill bottle with white pills spilling out.

Simple pain relievers are typically ineffective for centrally maintained pain. Opioids are also often ineffective and have many clinical and social problems that make their use problematic (12).

According to Crofford (2015), in reality, none of the available pharmacological treatments for long-term pain is particularly effective, and non-pharmacological treatments are difficult. Developing new strategies for the treatment of chronic pain is of the utmost urgency.

Therefore, it’s important to begin with a better understanding of the pathways that facilitate the transition from acute to chronic pain and the maintenance of chronic pain.

  • Crofford, L. J. (2015). Chronic pain: where the body meets the brain. Transactions of the American Clinical and Climatological Association, 126, 167.
  • Casals, M., & Samper, D. (2004). Epidemiología, prevalencia y calidad de vida del dolor crónico no oncológico: Estudio ITACA. Revista de la Sociedad Española del Dolor, 11(5), 260-269.
  • Woolf, C. J., & Mannion, R. J. (1999). Neuropathic pain: aetiology, symptoms, mechanisms, and management. The lancet, 353(9168), 1959-1964.
  • Global Industry Analysts, Inc. 2011. Available online at http://www.
  • Catala, E., Reig, E., Artes, M., Aliaga, L., López, J. S., & Segu, J. L. (2002). Prevalence of pain in the Spanish population telephone survey in 5000 homes. European journal of pain, 6(2), 133-140.
  • Smith, B. H., Elliott, A. M., Chambers, W. A., Smith, W. C., Hannaford, P. C., & Penny, K. (2001). The impact of chronic pain in the community. Family practice, 18(3), 292-299.
  • Viejo, M. Á. G., & Huerta, M. J. C. (2000). Incapacidad por dolor lumbar en España. Medicina clínica, 114(13), 491-492.
  • Kato, K., Sullivan, P. F., Evengård, B., & Pedersen, N. L. (2009). A population-based twin study of functional somatic syndromes. Psychological medicine, 39(3), 497-505.
  • Diatchenko, L., Fillingim, R. B., Smith, S. B., & Maixner, W. (2013). The phenotypic and genetic signatures of common musculoskeletal pain conditions. Nature Reviews Rheumatology, 9(6), 340.
  • Nicholl, B. I., Macfarlane, G. J., Davies, K. A., Morriss, R., Dickens, C., & McBeth, J. (2009). Premorbid psychosocial factors are associated with poor health-related quality of life in subjects with new onset of chronic widespread pain–results from the EPIFUND study. PAIN®, 141(1-2), 119-126.
  • Nes, L. S., Carlson, C. R., Crofford, L. J., de Leeuw, R., & Segerstrom, S. C. (2011). Individual differences and self-regulatory fatigue: Optimism, conscientiousness, and self-consciousness. Personality and individual differences, 50(4), 475-480.
  • Crofford, L. J. (2010). Adverse effects of chronic opioid therapy for chronic musculoskeletal pain. Nature Reviews Rheumatology, 6(4), 191.

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