Patient Assessment & Body Region Screening
A structured pain history begins the ACR 2016 workup.
- 19: Body regions screened (defined anatomical sites)
- ~2%: Estimated FM prevalence (of general population)
- ~2:1: Female-to-male ratio (in diagnosed cases)
- 20–55: Typical onset age (years, wide range)
Why a structured pain map
A checklist avoids missing or double-counting pain sites.
Standardized regions replace vague, inconsistent pain descriptions.
Bilateral symmetry in scoring
Left and right sides of paired regions count separately.
Replacing the 1990 tender-point exam
2016 criteria dropped manual tender-point palpation entirely.
WPI — Counting Painful Regions
The WPI totals how many of 19 regions hurt.
- 0–19: WPI range (one point per region)
- ≥7: WPI threshold (primary) (with SSS ≥5)
- 4–6: WPI threshold (alt) (with SSS ≥9)
- 7 days: Recall window (prior week of pain)
Scoring mechanics
Each affected region adds exactly one point, no weighting.
WPI reflects breadth of pain, not intensity.
Self-report basis
Patients mark regions themselves on a body diagram or questionnaire.
Distinguishing widespread from localized pain
Widespread pain spans multiple body quadrants and the axial skeleton.
SSS — Rating Fatigue, Sleep & Cognition
Four symptom domains are rated to build the SSS total.
- 0–12: SSS range (sum of four domains)
- 0–3: Core symptom scale (each, three domains)
- 0–3: Somatic symptom count (added to core score)
- ≥5: SSS threshold (primary) (with WPI ≥7)
Three core symptom domains
Fatigue, unrefreshing sleep, and cognitive trouble each scored 0–3.
Severity, not just presence, drives the SSS score.
Somatic symptom burden
Headache, IBS, and other complaints add a fourth component.
Why severity matters alongside spread
SSS captures how disruptive symptoms are, not just where.
Combined Criteria — WPI × SSS Thresholds
Two scores and two extra conditions decide the diagnosis.
- WPI≥7: Primary rule (and SSS ≥5)
- WPI 4–6: Alternate rule (and SSS ≥9)
- ≥3 mo: Duration requirement (symptoms present)
- None: Exclusion requirement (better-explaining diagnosis)
Two paths to the same outcome
Either threshold combination satisfies the pain-and-severity requirement.
Lower pain spread can still qualify with higher severity.
Chronicity requirement
Symptoms must persist at a similar level for three months.
Ruling out other explanations
No other disorder should better explain the symptom pattern.
Fibromyalgia Diagnosis or Continued Workup
The threshold check resolves into one of two outcomes.
- FM Dx: Outcome A (criteria fully satisfied)
- Workup: Outcome B (criteria not satisfied)
- Clinical: Diagnosis type (no lab test confirms FM)
- Ongoing: Reassessment (symptoms can fluctuate over time)
Criteria met — diagnosis assigned
Fibromyalgia is diagnosed when both score and duration hold.
Diagnosis does not require excluding all other conditions.
Criteria not met — alternative workup
Clinicians pursue other causes for the reported symptoms.
A living, fluctuating score
WPI and SSS can be reassessed as symptoms change.