Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 3 complete abstracts (920 words), 9 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
Aching sensation that persists for more than a few months. It may or may not be associated with trauma or disease, and may persist after the initial injury has healed. Its localization, character, and timing are more vague than with acute pain.
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: Pain, Chronic; Widespread Chronic Pain; Chronic Pain, Widespread; Pain, Widespread Chronic; Chronic Primary Pain; Pain, Chronic Primary; Primary Pain, Chronic; Chronic Secondary Pain.
Where it fits in the MeSH classification
- Broader topics
- Pain
- See also
- Acute Pain
Research landscape
PubMed indexes 30,939 records tagged with the MeSH heading “Chronic Pain” (counts retrieved 2026-10-29). 16,268 of them (52.6%) were published from 2020 onward, and the busiest period so far is 2020 onward with 16,268 records.
Reviews account for 6,831 records (22.1%) and meta-analyses for 1,155. Randomized controlled trials number 2,858 (9.2%) as a share of all records on the topic. Randomized trials make up a comparatively large share of this literature, which means many treatment questions have been tested directly.
Show the data
| Period | Records |
|---|---|
| through 1999 | 0 |
| 2000-2009 | 24 |
| 2010-2019 | 14,980 |
| 2020 onward | 16,268 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 6,831 | 22.1% |
| Meta-analyses | 1,155 | 3.7% |
| Randomized controlled trials | 2,858 | 9.2% |
Method: PubMed query "Chronic Pain"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-29.
Reading the evidence in neuroscience
Neuroscience draws on tools with different strengths: cellular and animal work can manipulate circuits directly, while human imaging and electrophysiology observe the living brain at lower resolution. Small imaging studies are prone to false positives, and findings in animals do not always carry over to people. Clinical neurology and psychiatry rely on trials and cohort studies whose outcomes are often symptom scales. Check the species, the sample size, how the outcome was measured and whether results were replicated.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
| Study / authors | Year | Source label / design | Europe PMC citations | Licence / source |
|---|---|---|---|---|
| Chronic Overlapping Pain and Central Sensitization in Chronic Pelvic Pain: Do Positive and Negative Affect Play a Role? | 2026 | Research article Design not recorded in structured metadata | 3 | cc by PMID 42199153 · DOI · PMC13213334 |
| Efficacy of Various Virtual Reality Exposure Therapies for Chronic Low Back Pain: Systematic Review and Network Meta-Analysis | 2026 | Systematic review Design not recorded in structured metadata | 2 | cc by PMID 42489003 · DOI · PMC13392656 |
| Single-label and multi-label classification for disease recognition with special consideration of comorbidities | 2026 | Research article Design not recorded in structured metadata | 2 | cc by PMID 42432509 · DOI · PMC13355337 |
Chronic Overlapping Pain and Central Sensitization in Chronic Pelvic Pain: Do Positive and Negative Affect Play a Role? [1]
Abstract reading summary — source excerpts
- Opening excerpt
- Chronic pelvic pain (CPP) has a complex etiology and a high degree of coprevalence with other chronic overlapping pain conditions (COPCs).
- Closing excerpt
- Individuals with CPP, especially those experiencing multiple chronic pain conditions, may benefit from interventions aimed at increasing positive affect.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (235 words)
Chronic pelvic pain (CPP) has a complex etiology and a high degree of coprevalence with other chronic overlapping pain conditions (COPCs). Evidence suggests that central sensitization contributes to these conditions; however, the psychological risk and resilience factors influencing the relationship between COPCs and central sensitization have received limited attention. Therefore, the aim of this study was to examine whether positive and negative affect moderate the relationship between COPCs and central sensitization in individuals with CPP. Participants (N = 197) completed the Central Sensitization Inventory and Positive and Negative Affect Schedule and self-reported the presence of diagnosed COPCs. Results indicated that greater symptoms of central sensitization were associated with a greater number of COPCs (p < 0.01). Higher levels of positive affect were related to lower central sensitization (p < 0.01) and fewer COPCs (p < 0.05), while higher negative affect was associated with greater central sensitization (p < 0.01). After controlling for pelvic pain duration, a greater number of COPCs were associated with greater central sensitization, but only among individuals with lower positive affect (p = 0.01). No significant moderation effects were observed for negative affect (p = 0.13). The findings from this cross-sectional study suggest that lower positive affect may have an adverse effect on central sensitization in those with a greater number of COPCs. Individuals with CPP, especially those experiencing multiple chronic pain conditions, may benefit from interventions aimed at increasing positive affect.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42199153 · DOI · PMC13213334
Efficacy of Various Virtual Reality Exposure Therapies for Chronic Low Back Pain: Systematic Review and Network Meta-Analysis [2]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundChronic low back pain (CLBP) is a major global health challenge.
- Closing excerpt
- More RCTs are needed to provide robust clinical evidence.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (429 words)
BackgroundChronic low back pain (CLBP) is a major global health challenge. While nonpharmacological therapies are recommended, patient compliance is often hindered by kinesiophobia. Virtual reality (VR) offers an immersive, distraction-based approach, but the comparative effectiveness of different VR modalities remains unclear.ObjectiveThe aim of the study is to compare and rank the efficacy of different VR-based training modalities on pain intensity, disability, and kinesiophobia in patients with CLBP.MethodsSystematic searches were conducted in PubMed, Web of Science, Scopus, Embase, CINAHL, and the Cochrane Library from inception until June 2025. Randomized controlled trials (RCTs) assessing the effects of VR-based training on individuals with CLBP were selected. Primary outcomes were pain intensity, disability (Oswestry Disability Index), and kinesiophobia (Tampa Scale of Kinesiophobia). The Cochrane Risk of Bias 2 tool was used for quality assessment. Confidence in Network Meta-Analysis (CINeMA) framework was used to evaluate the credibility of cumulative evidence. A Bayesian network meta-analysis with standardized mean difference (SMD) as effect size was performed to synthesize evidence and rank interventions using surface under the cumulative ranking curve values. The GRADE (Grading of Recommendations Assessment, Development and Evaluation) framework was adapted to evaluate the quality of evidence.ResultsIn total, 25 RCTs with a total of 2610 participants were included in the analysis. For pain intensity, shooting games (SMD -4.40, 95% credible interval [CrI] -6.80 to -2.20) and VR-based equestrian training (SMD -2.00, 95% CrI -3.70 to -0.57) were significantly superior to all types of controls. Surface under the cumulative ranking curve indicated that shooting games had the highest probability (98%) of being the most effective intervention for pain relief. For disability, no intervention demonstrated statistically significant superiority. For kinesiophobia, shooting games (SMD -3.40, 95% CrI -5.60 to -1.10) significantly outperformed traditional exercise controls. The quality of evidence ranged from very low to moderate across outcomes.ConclusionsThis first network meta-analysis to compare and rank distinct VR modalities for CLBP offers several key innovations and contributions to the field. By moving beyond aggregate VR categorizations, we provide a granular, comparative ranking of specific, actionable VR interventions. Unlike previous reviews that treated VR as a homogeneous group or only compared it to sham, our network meta-analysis directly and indirectly compares 7 distinct VR modalities, revealing that not all VR is equally effective. Our findings suggest that shooting games have the potential to be the most effective VR therapy for relieving pain intensity and kinesiophobia, though evidence for disability remains limited. Unfortunately, due to heterogeneity and low-quality evidence, there is no evidence demonstrating significant improvement in specific outcomes for patients with CLBP. More RCTs are needed to provide robust clinical evidence.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42489003 · DOI · PMC13392656
Single-label and multi-label classification for disease recognition with special consideration of comorbidities [3]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundCertain diseases require rapid treatment to avoid long-term consequences for patients.
- Closing excerpt
- Our results thus lead to the point that computational prediction tools should serve as decision support for treating physicians, but never replace their clinical judgment.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (256 words)
BackgroundCertain diseases require rapid treatment to avoid long-term consequences for patients. However, they may be difficult to recognize, especially if the symptoms are ambiguous and compatible with multiple possible diagnoses. Completing all necessary examinations often takes time, thereby prolonging patient suffering. Data-driven approaches, such as single-label classification (SLC) and multi-label classification (MLC), can help accelerate the diagnostic process and improve accuracy.MethodsComparing SLC and MLC allows us to investigate whether disease recognition benefits from considering comorbidities. In this context, we aim to provide a conceptual framing of (differences between) the two approaches in model formulation, decision spaces and handling of class imbalance. To empirically assess their performance, we conduct a case study applying SLC and MLC to data from chronic pain patients.ResultsOur analysis yields an ambiguous picture of whether incorporating comorbidities improves disease recognition. The suitability of SLC and MLC is determined by multiple factors, notably the dependency structure among diseases and between diseases and covariates, as well as by data characteristics such as class imbalance. Consequently, it is of high importance to address each individual problem in an individual manner, especially when the implications can be significant, such as in patient referrals.ConclusionOur study highlights the importance of considering the specific characteristics of the data when selecting an appropriate classification approach for disease recognition and beyond. We illustrate how underlying assumptions, learning structures, and strategies for handling class imbalance shape predictive performance. Our results thus lead to the point that computational prediction tools should serve as decision support for treating physicians, but never replace their clinical judgment.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42432509 · DOI · PMC13355337
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article The prevalence of chronic pain in children and adolescents: a systematic review update and meta-analysis [4]
- Research article A meta-analysis of the associations of elements of the fear-avoidance model of chronic pain with negative affect, depression, anxiety, pain-related disability and pain intensity [5]
- Research article Prevalence of Depression and Anxiety Among Adults With Chronic Pain: A Systematic Review and Meta-Analysis [6]
- Research article Prevalence, Incidence, and Factors Associated With Non-Specific Chronic Low Back Pain in Community-Dwelling Older Adults Aged 60 Years and Older: A Systematic Review and Meta-Analysis [7]
- Research article Some types of exercise are more effective than others in people with chronic low back pain: a network meta-analysis [8]
- Research article Efficacy and safety of transcutaneous electrical nerve stimulation (TENS) for acute and chronic pain in adults: a systematic review and meta-analysis of 381 studies (the meta-TENS study) [9]
References
- Palit S, Alappattu MJ, Wilson JM, Heft JS, Bartley EJ. Chronic Overlapping Pain and Central Sensitization in Chronic Pelvic Pain: Do Positive and Negative Affect Play a Role?. . 2026. PMID 42199153 · DOI · PMC13213334
- Wu L, Liu X, Yin Q, Yao T, Li Y. Efficacy of Various Virtual Reality Exposure Therapies for Chronic Low Back Pain: Systematic Review and Network Meta-Analysis. . 2026. PMID 42489003 · DOI · PMC13392656
- Schmiegel S, Marchi H, Röchter MH, Rudwaleit M, Fuchs C. Single-label and multi-label classification for disease recognition with special consideration of comorbidities. . 2026. PMID 42432509 · DOI · PMC13355337
- Chambers CT, Chambers CT, Dol J, Tutelman PR, Langley CL, Parker JA, et al.. The prevalence of chronic pain in children and adolescents: a systematic review update and meta-analysis. Pain. 2024. PMID 38743558 · DOI · PMC11404345
- Rogers AH, Farris SG. A meta-analysis of the associations of elements of the fear-avoidance model of chronic pain with negative affect, depression, anxiety, pain-related disability and pain intensity. Eur J Pain. 2022. PMID 35727200 · DOI · PMC9541898
- Aaron RV, Ravyts SG, Carnahan ND, Bhattiprolu K, Harte N, McCaulley CC, et al.. Prevalence of Depression and Anxiety Among Adults With Chronic Pain: A Systematic Review and Meta-Analysis. JAMA Netw Open. 2025. PMID 40053352 · DOI · PMC11889470
- Wong CK, Mak RY, Kwok TS, Tsang JS, Leung MY, Funabashi M, et al.. Prevalence, Incidence, and Factors Associated With Non-Specific Chronic Low Back Pain in Community-Dwelling Older Adults Aged 60 Years and Older: A Systematic Review and Meta-Analysis. J Pain. 2022. PMID 34450274 · DOI
- Hayden JA, Ellis J, Ogilvie R, Stewart SA, Bagg MK, Stanojevic S, et al.. Some types of exercise are more effective than others in people with chronic low back pain: a network meta-analysis. J Physiother. 2021. PMID 34538747 · DOI
- Johnson MI, Paley CA, Jones G, Mulvey MR, Wittkopf PG. Efficacy and safety of transcutaneous electrical nerve stimulation (TENS) for acute and chronic pain in adults: a systematic review and meta-analysis of 381 studies (the meta-TENS study). BMJ Open. 2022. PMID 35144946 · DOI · PMC8845179
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-10-31; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-10-29.
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Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.