schema: eds-research/corpus/v1
category:
  id: comorbidities
  label: Comorbidities and systemic features
  description: The multisystem reality — dysautonomia and POTS, MCAS, GI, pain, fatigue, and the comorbidity structure the community named before the literature did.
  order: 40
records:
  - id: com-trifecta-pattern
    kind: signal
    title: The "trifecta" — hEDS, POTS/dysautonomia, and MCAS co-clustering
    summary: "Patient communities converged on the hEDS–POTS–MCAS triad years before it appeared in clinical reviews. Registry data now supports the clustering: in the Global Registry survey (n=505), POTS and mast cell activation syndrome were among the alternative diagnoses participants most endorsed as accurate. The triad is community-coined and increasingly clinically studied; the mechanism remains unexplained."
    subtypes: [heds, hsd]
    status: community-signal
    criteria_era: international-2017
    evidence:
      - stratum: community
        tier: cross-venue-pattern
        source_ids: [source-ec36295ad04f34148c63, source-641ce29242a70e8a5f01]
        note: Recurring across Reddit and Inspire over multiple years.
      - stratum: registry
        tier: registry-analysis
        source_ids: [source-d4a910b62f451448889e]
        note: POTS and MCAS among the most-endorsed comorbid diagnoses.
    corroboration: convergent
    venues: [venue-reddit-ehlersdanlos, venue-inspire-eds-hsd]
    reviewed_at: "2026-09-16"
    reassess_by: "2026-12-16"
    tags: [dysautonomia, mcas, trifecta]
  - id: com-multisystem-2017
    kind: finding
    title: The 2017 criteria formalized multisystem involvement
    summary: The 2017 classification moved EDS from a skin-and-joints frame to an explicitly multisystem one — systemic manifestations entered the hEDS criteria themselves, and companion papers covered GI, cardiovascular-autonomic, pain, and psychiatric comorbidity. This codified what patient communities had long reported.
    date: "2017-03"
    date_precision: month
    subtypes: [all-eds]
    status: established
    criteria_era: international-2017
    evidence:
      - stratum: clinical
        tier: consensus-statement
        source_ids: [source-36ad1cab53c4cea4f4b4]
      - stratum: clinical
        tier: expert-review
        source_ids: [source-1ad3f0edd57e0fab1524]
    reviewed_at: "2026-09-16"
    tags: [multisystem]
  - id: com-misdiagnosis-load
    kind: finding
    title: hEDS patients average ten alternative diagnoses before confirmation
    summary: The Global Registry survey (n=505, clinically confirmed hEDS) found a mean of 10.45 alternative diagnoses — most commonly anxiety, depression, and migraine — with functional neurological disorder and multiple sclerosis among the most-rejected labels. Post-diagnosis, participants most endorsed POTS, cervical instability, and MCAS as accurate.
    date: "2024"
    date_precision: year
    subtypes: [heds]
    status: established
    criteria_era: international-2017
    evidence:
      - stratum: registry
        tier: registry-analysis
        source_ids: [source-d4a910b62f451448889e]
      - stratum: clinical
        tier: cohort-study
        source_ids: [source-21337422dde3976b584c]
        note: Qualitative confirmation — dismissal and misdiagnosis recur through the diagnostic odyssey literature.
    corroboration: convergent
    reviewed_at: "2026-09-16"
    tags: [misdiagnosis, registry]
  - id: com-cci-tethered-cord
    kind: finding
    title: Craniocervical instability and tethered cord — the contested frontier
    summary: Craniocervical instability and tethered-cord claims circulate strongly in community venues and some surgical case series, and CCI was among the most-endorsed diagnoses in the registry survey. Controlled evidence remains limited and surgical intervention carries real risk; this index marks the area contested rather than dismissing it.
    subtypes: [heds, ceds]
    status: contested
    criteria_era: international-2017
    evidence:
      - stratum: community
        tier: cross-venue-pattern
        source_ids: [source-ec36295ad04f34148c63, source-641ce29242a70e8a5f01]
      - stratum: registry
        tier: registry-analysis
        source_ids: [source-d4a910b62f451448889e]
        note: CCI among most-endorsed alternative diagnoses in the registry survey.
    corroboration: convergent
    venues: [venue-reddit-ehlersdanlos, venue-inspire-eds-hsd]
    reviewed_at: "2026-09-16"
    reassess_by: "2026-12-16"
    tags: [cci, tethered-cord, contested]
  - id: com-gi-dysautonomia-cluster
    kind: finding
    title: GI dysmotility and autonomic features are documented comorbidity domains
    summary: The 2017 series and subsequent cohort work document gastrointestinal dysmotility (reflux, gastroparesis, constipation) and autonomic dysfunction (orthostatic intolerance, POTS) as leading comorbidity domains in hEDS/HSD. The German 2025 cohort shows musculoskeletal pain and joint instability as the dominant presenting manifestations.
    subtypes: [heds, hsd]
    status: probable
    criteria_era: international-2017
    evidence:
      - stratum: clinical
        tier: expert-review
        source_ids: [source-1ad3f0edd57e0fab1524]
      - stratum: clinical
        tier: cohort-study
        source_ids: [source-de164233cddfefc4105a]
    reviewed_at: "2026-09-16"
    tags: [gi, dysautonomia]