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Rheumatology
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Pain Medicine

Fibromyalgia

Moderate EvidenceUpdated: 2025-12-24

On This Page

Red Flags

  • Inflammatory features (swelling, morning stiffness >1 hour)
  • Weight loss
  • Focal neurological signs
  • New onset in elderly (consider malignancy)
Overview

Fibromyalgia

1. Clinical Overview

Summary

Fibromyalgia is a chronic condition characterised by widespread musculoskeletal pain, fatigue, sleep disturbance, and cognitive dysfunction ("fibro fog"). It is a diagnosis of exclusion — investigations are normal. The pathophysiology involves central sensitisation with amplified pain processing in the CNS. Diagnosis is clinical, based on the widespread pain index (WPI) and symptom severity scale (SSS). Management is multidisciplinary: patient education, graded aerobic exercise, and pharmacological options including amitriptyline, duloxetine, and pregabalin. Cognitive behavioural therapy (CBT) is also effective. The condition is chronic but not progressive or life-threatening.

Key Facts

  • Prevalence: 2-8% of population; Female:Male = 2:1
  • Features: Widespread pain, Fatigue, Sleep disturbance, Cognitive symptoms
  • Diagnosis: Clinical; Normal investigations
  • Not inflammatory: Normal CRP, ESR
  • Comorbidities: Depression, Anxiety, IBS, Chronic fatigue syndrome
  • Treatment: Exercise (first-line); Amitriptyline; Duloxetine; Pregabalin; CBT

Clinical Pearls

"Normal Bloods + Widespread Pain = Fibromyalgia": If inflammatory markers are normal and there's no objective inflammation, think fibromyalgia. Don't over-investigate.

"Central Sensitisation": Fibromyalgia is not a peripheral problem — it's central pain amplification. The pain is real but generated by abnormal CNS processing.

"Exercise Is First-Line": Graded aerobic exercise is the most evidence-based intervention. Start low, go slow.

"Amitriptyline Helps Sleep and Pain": Low-dose amitriptyline (10-25 mg at night) improves sleep and reduces pain through central mechanisms.

"Address the Comorbidities": Depression, anxiety, and sleep disorders are common. Treating these improves overall outcomes.

Why This Matters Clinically

Fibromyalgia is common and often poorly managed. Patients frequently feel dismissed. Acknowledging the reality of their symptoms, providing education, and using evidence-based treatments improves quality of life.[1,2]


2. Epidemiology

Incidence & Prevalence

ParameterData
Prevalence2-8% of population
SexFemale:Male = 2-3:1
AgePeak 30-50 years

Risk Factors

FactorNotes
Female sexHigher prevalence
Family historyGenetic component
Physical traumaMay trigger onset
Psychological stressMay trigger or worsen
Other chronic pain conditionsIBS, TMJ, Chronic headache

3. Pathophysiology

Central Sensitisation

FeatureDetails
Abnormal pain processingAmplification of pain signals in CNS
Reduced descending inhibitionImpaired pain modulation
Neurotransmitter abnormalitiesSubstance P increased; Serotonin, Norepinephrine decreased
Functional MRIIncreased activation of pain-processing regions

This Is NOT an Inflammatory Condition

  • No joint swelling
  • No synovitis
  • Normal CRP, ESR
  • Normal imaging
  • Autoantibodies negative

4. Clinical Presentation

Core Symptoms

SymptomNotes
Widespread painAxial + Upper and lower body; Both sides; >3 months
FatiguePersistent, unrefreshing
Sleep disturbanceNon-restorative sleep; Waking unrefreshed
Cognitive symptoms"Fibro fog" — Poor concentration, memory

Associated Symptoms

SymptomPrevalence
HeadachesCommon
IBS-like symptoms30-70%
ParaesthesiaWithout objective neuropathy
SensitivityTo light, noise, temperature
Depression/Anxiety30-50%

Signs

SignFinding
Tender pointsMultiple areas of tenderness (no longer required for diagnosis)
No joint swellingKey distinguishing feature from inflammatory arthritis
No synovitisNo heat, effusion
Normal neurological examImportant to exclude neuropathy

Red Flags

[!CAUTION] Consider alternative diagnosis if:

  • Objective joint swelling or synovitis
  • Morning stiffness >1 hour (inflammatory)
  • Weight loss
  • Focal neurological signs
  • New onset in elderly

5. Clinical Examination

Musculoskeletal

FindingNotes
Widespread tendernessMultiple sites; Not localised to joints
No synovitisNo swelling, warmth, effusion
Normal range of motion

Neurological

  • Normal power, reflexes, sensation
  • Excludes peripheral neuropathy

6. Investigations

Purpose

Investigations are to exclude other diagnoses, not to confirm fibromyalgia.

InvestigationPurposeExpected Finding
FBCAnaemia, infectionNormal
CRP / ESRInflammationNormal
TFTsHypothyroidismNormal
Vitamin DDeficiency causes painCheck and correct
Rheumatoid factor, Anti-CCPRANegative
ANACTDUsually negative

Diagnostic Criteria (2016 ACR)

ComponentCriteria
Widespread Pain Index (WPI)Score ≥7
Symptom Severity Scale (SSS)Score ≥5
ORWPI 4-6 AND SSS ≥9
Duration>3 months
No other explanationAfter clinical assessment

7. Management

Management Algorithm

             FIBROMYALGIA MANAGEMENT
                       ↓
┌───────────────────────────────────────────────────────────┐
│              EDUCATION & REASSURANCE                      │
├───────────────────────────────────────────────────────────┤
│  ➤ Validate the patient's pain — it is real             │
│  ➤ Explain central sensitisation                        │
│  ➤ Set realistic expectations — chronic but manageable  │
│  ➤ Avoid over-investigation                             │
└───────────────────────────────────────────────────────────┘
                       ↓
┌───────────────────────────────────────────────────────────┐
│           NON-PHARMACOLOGICAL (FIRST-LINE)                │
├───────────────────────────────────────────────────────────┤
│  ➤ Graded aerobic exercise (walking, swimming, cycling) │
│    • Start low, increase gradually                       │
│    • Most evidence-based intervention                    │
│  ➤ CBT (Cognitive Behavioural Therapy)                   │
│  ➤ Sleep hygiene                                          │
│  ➤ Stress management                                      │
│  ➤ Hydrotherapy                                           │
└───────────────────────────────────────────────────────────┘
                       ↓
┌───────────────────────────────────────────────────────────┐
│               PHARMACOLOGICAL OPTIONS                     │
├───────────────────────────────────────────────────────────┤
│  FIRST-LINE:                                               │
│  ➤ Amitriptyline 10-75 mg at night                       │
│    • Helps pain and sleep                                │
│                                                           │
│  ➤ Duloxetine 30-60 mg daily                             │
│    • SNRI; Good if coexisting depression                 │
│                                                           │
│  ➤ Pregabalin 75-300 mg BD                               │
│    • Evidence for pain reduction; Also helps anxiety     │
│                                                           │
│  SECOND-LINE:                                              │
│  ➤ Gabapentin                                             │
│  ➤ Tramadol (short-term only; avoid long-term opioids)   │
│                                                           │
│  AVOID:                                                    │
│  ➤ Strong opioids — not effective; Risk of dependency   │
│  ➤ NSAIDs — not effective (no inflammation)              │
│  ➤ Corticosteroids — no role                             │
└───────────────────────────────────────────────────────────┘
                       ↓
┌───────────────────────────────────────────────────────────┐
│            TREAT COMORBIDITIES                             │
├───────────────────────────────────────────────────────────┤
│  ➤ Depression: SSRIs/SNRIs                                │
│  ➤ Anxiety: CBT, SSRIs, Pregabalin                       │
│  ➤ Sleep disorder: Sleep hygiene; Low-dose amitriptyline │
│  ➤ IBS: Dietary modification                              │
└───────────────────────────────────────────────────────────┘

8. Complications
ComplicationNotes
DisabilityReduced work capacity; QoL impact
Depression/AnxietyCommon; Worsens pain perception
Medication side effectsWeight gain; Drowsiness
Opioid dependenceIf inappropriately prescribed

9. Prognosis & Outcomes
FactorOutcome
ChronicLifelong condition; Not progressive
Not life-threateningDoes not affect life expectancy
VariableSome improve; Some remain symptomatic
Better outcomesWith exercise adherence and addressing comorbidities

10. Evidence & Guidelines

Key Guidelines

GuidelineOrganisationYearKey Points
EULAR Fibromyalgia RecommendationsEULAR2017Exercise first-line; Individualised pharmacotherapy

11. Patient/Layperson Explanation

What is fibromyalgia?

Fibromyalgia is a long-term condition that causes widespread pain throughout the body. It's often accompanied by tiredness, sleep problems, and difficulty concentrating.

What causes it?

The exact cause is unknown, but it's thought to involve changes in how the brain and spinal cord process pain signals, making them more sensitive.

What are the symptoms?

  • Pain all over the body
  • Feeling tired all the time
  • Poor sleep
  • "Brain fog" — trouble thinking clearly
  • Headaches, gut problems

How is it treated?

  • Exercise: Regular gentle exercise (walking, swimming) is the most helpful treatment
  • Medications: Tablets like amitriptyline, duloxetine, or pregabalin can help
  • Talking therapies: CBT can help manage pain
  • Lifestyle: Good sleep habits, stress management

Is it serious?

Fibromyalgia is not dangerous and doesn't damage your joints or muscles. It can affect daily life, but many people learn to manage it well.


12. References
  1. Macfarlane GJ, Kronisch C, Dean LE, et al. EULAR revised recommendations for the management of fibromyalgia. Ann Rheum Dis. 2017;76(2):318-328. PMID: 27377815

13. Examination Focus

High-Yield Exam Topics

TopicKey Points
DiagnosisClinical; WPI + SSS; Normal investigations
Not inflammatoryNormal CRP, ESR; No synovitis
First-line treatmentGraded aerobic exercise
PharmacologicalAmitriptyline, Duloxetine, Pregabalin
AvoidStrong opioids; NSAIDs; Steroids
Central sensitisationKey pathophysiology

Sample Viva Question

Q: A patient presents with widespread pain and fatigue. Investigations are normal. How would you diagnose and manage fibromyalgia?

Model Answer: I would diagnose fibromyalgia clinically using the 2016 ACR criteria: Widespread Pain Index ≥7 and Symptom Severity Scale ≥5, with symptoms present for >3 months and no other explanation. Key investigations to exclude differentials: FBC, CRP, ESR, TFTs, Vitamin D — all normal in fibromyalgia.

Management:

  1. Education: Validate symptoms; Explain central sensitisation
  2. Non-pharmacological (first-line): Graded aerobic exercise; CBT
  3. Pharmacological: Amitriptyline 10-25 mg at night (helps sleep and pain); OR Duloxetine if depression coexists; OR Pregabalin for pain and anxiety
  4. Avoid: Strong opioids (ineffective and harmful); NSAIDs (no inflammation)

Address comorbidities: depression, anxiety, sleep disorder.


Last Reviewed: 2025-12-24 | MedVellum Editorial Team

Last updated: 2025-12-24

At a Glance

EvidenceModerate
Last Updated2025-12-24

Red Flags

  • Inflammatory features (swelling, morning stiffness >1 hour)
  • Weight loss
  • Focal neurological signs
  • New onset in elderly (consider malignancy)

Clinical Pearls

  • **"Normal Bloods + Widespread Pain = Fibromyalgia"**: If inflammatory markers are normal and there's no objective inflammation, think fibromyalgia. Don't over-investigate.
  • **"Central Sensitisation"**: Fibromyalgia is not a peripheral problem — it's central pain amplification. The pain is real but generated by abnormal CNS processing.
  • **"Exercise Is First-Line"**: Graded aerobic exercise is the most evidence-based intervention. Start low, go slow.
  • **"Amitriptyline Helps Sleep and Pain"**: Low-dose amitriptyline (10-25 mg at night) improves sleep and reduces pain through central mechanisms.
  • **"Address the Comorbidities"**: Depression, anxiety, and sleep disorders are common. Treating these improves overall outcomes.

Guidelines

  • NICE Guidelines
  • BTS Guidelines
  • RCUK Guidelines