Fibromyalgia

Meet the patient

A 42-year-old teaching assistant arrives with a folder of normal blood tests and a weary expression. For two years her whole body has ached "like flu, all the time". She wakes unrefreshed, cannot concentrate at work, and has irritable bowel symptoms and headaches. Every joint and muscle is tender. She has seen four specialists, been told "all your tests are normal", and is now on escalating oxycodone that has stopped helping.[1]

Three questions decide her next year, and they decide every fibromyalgia consult: is the pain real? (yes — central sensitisation is a genuine neurological phenomenon), is there an inflammatory or organic mimic hiding inside it? (baseline tests exclude the treatable ones), and what will actually help her function? (graded exercise and CBT outperform any tablet she is taking). The two greatest iatrogenic dangers — over-investigation and opioid escalation — are both already active in her story.[1]

What fibromyalgia is — and the three things it is not

It is a disorder of pain amplification. The central nervous system processes ordinary sensory input as painful (allodynia) and exaggerates the response to genuinely noxious stimuli (hyperalgesia), in the complete absence of tissue injury, inflammation or nerve damage. It is the prototype of nociplastic pain — formally defined by the International Association for the Study of Pain in 2017 and embedded in ICD-11, sitting alongside nociceptive pain (osteoarthritis, fracture) and neuropathic pain (diabetic neuropathy). All three can coexist, which is why a rheumatoid arthritis patient can also have fibromyalgia.[1]

It is not a diagnosis of exclusion. The older teaching — endless negative tests, then "it must be fibromyalgia" — is obsolete. The ACR 2016 criteria allow a confident, positive, criteria-based diagnosis, and a fibromyalgia label is now explicitly permitted alongside other clinical diagnoses. A patient with rheumatoid arthritis can also have fibromyalgia; neither cancels the other.[1][3]

It is not "all in the head". The pain is real and brain-generated. Functional neuroimaging shows augmented activation of pain-matrix regions (insula, anterior cingulate, somatosensory cortex) in response to pressures healthy controls do not even register as painful. Saying "all in the nervous system" is emphatically not saying it is imagined — and a clinician who conveys the opposite reproduces the harm these patients have already absorbed.[1]

It is not inflammatory, destructive or life-shortening. Fibromyalgia causes no joint damage, no organ failure and no reduction in life expectancy. Its morbidity lies in functional impairment and in the iatrogenic harms that accumulate when it is mismanaged — chiefly opioids and over-investigation.[1]

Three pain mechanisms — nociplastic sits between the other two

The single most useful concept is the three-mechanism split, because each mechanism has its own drug class and its own non-drug therapy. Naming the mechanism names the treatment.[1]

[1]

The discriminator line: widespread, migrating, non-dermatomal pain with a normal examination and normal bloods is nociplastic until shown otherwise. Localised and proportional is nociceptive; burning and dermatomal is neuropathic. All three can coexist, and recognising each lets you treat each.[1]

The 2016 criteria — a positive diagnosis, not a tender-point count

The diagnosis has moved decisively away from counting tender points. The 1990 ACR criteria required 11 of 18 tender points, a manoeuvre that is subjective, poorly reproducible and biased toward rheumatology expertise. Know it for the viva; do not use it to diagnose. The 2016 revision is the current international standard.[1][4]

The ACR 2016 criteria diagnose fibromyalgia when WPI is 7 or more AND SSS is 5 or more, OR when WPI is 4 to 6 AND SSS is 9 or more, provided symptoms have been present at a similar level for at least 3 months — and, crucially, a fibromyalgia diagnosis is permitted alongside other clinical diagnoses.[1][3]

Calculate the two scores at the bedside. The Widespread Pain Index (WPI, 0 to 19) counts 19 defined body areas reported as painful in the last week — left and right shoulder girdle, upper arm, lower arm, hip or buttock, upper leg and lower leg, plus the jaw (left and right), chest, abdomen, upper back, lower back and neck. The Symptom Severity Scale (SSS, 0 to 12) scores fatigue, waking unrefreshed, and cognitive symptoms each from 0 to 3, then adds one point each (maximum 3) for headache, lower-abdominal pain or cramps, and depression or nausea over the previous 6 months.[1][3]

[1] [3]

How common, and why the syndromes cluster

Fibromyalgia is one of the most common chronic pain conditions — population prevalence of roughly 2 to 8 percent. It is far more common in women (female-to-male ratio about 7 to 9 to 1) and typically begins between 30 and 60 years, though juvenile and elderly forms exist. The diagnosis is often delayed by years, especially in men and in patients whose primary presentation is fatigue or mood rather than pain.[1]

[1]

The defining epidemiological feature is that the central sensitisation syndromes travel together. Fibromyalgia clusters with irritable bowel syndrome, chronic fatigue syndrome, tension and migraine headache, temporomandibular joint disorder, interstitial cystitis and chronic pelvic pain — all sharing a common disturbance in central sensory processing. This is why a fibromyalgia patient so often accumulates apparently independent diagnoses across many specialties over many years.[1]

Depression and anxiety occur in 30 to 60 percent, and the relationship is bidirectional — each worsens the other. Treating mood disorder is not optional decoration; it independently improves pain and function. The predisposing and triggering factors — female sex, family history (polygenic: serotonin-transporter, COMT and dopamine-receptor variants), physical trauma or surgery, serious infection (hepatitis, Lyme, Q fever, post-SARS-CoV-2 syndromes), psychological stress, adverse childhood experiences, and chronic sleep disturbance — all lower the threshold at which the central nervous system becomes persistently sensitised.[1]

Why it hurts — central sensitisation and the neurochemistry

The pathology is functional, not structural. There is no tissue inflammation, no joint damage, no muscle abnormality on histology, and no nerve lesion. The disturbance lies in how the central nervous system processes sensory signals. The cardinal phenomenon is central sensitisation: a state of heightened excitability of nociceptive neurons in the dorsal horn and supraspinal relay centres, so normal incoming traffic is amplified and mislabelled as pain.[1]

Two complementary mechanisms drive it. The first is temporal summation (the "wind-up" phenomenon): repeated low-intensity C-fibre input causes progressive NMDA-receptor-driven depolarisation of dorsal-horn neurons, so a stimulus that initially feels like touch increasingly registers as pain — and the receptive field expands, explaining the migrating, widespread quality. The second is impaired descending inhibition: the brain normally damps incoming nociceptive traffic via serotonergic and noradrenergic pathways; in fibromyalgia that brake fails, so signals pass through unchecked.[1]

The neurochemical imbalance is the most examinable single fact on the page — remember it as HIGH and LOW.[1]

[1]

This neurochemistry directly rationalises the drug classes that work: agents that boost serotonin and noradrenaline (SNRIs and tricyclics) or dampen excitatory transmission (the alpha-2-delta ligands pregabalin and gabapentin). Agents that suppress inflammation — corticosteroids, immunosuppressants, biologics — have no target here and no role.[1]

The sleep anomaly is viva gold. Fibromyalgia patients show the alpha-delta sleep anomaly — alpha-wave activity intrudes into non-REM slow-wave sleep, fragmenting deep restorative rest. It correlates tightly with waking unrefreshed and with next-day pain amplification, creating a vicious cycle in which poor sleep worsens pain and pain worsens sleep. This is why sleep hygiene and sedating adjuncts (amitriptyline, pregabalin) are therapeutically valuable. Polysomnography is not required for diagnosis.[1]

The clinical constellation — and the conspicuously normal examination

Fibromyalgia presents as a symptom cluster, and recognising both the constellation and the absence of objective abnormality is the diagnostic key.[1]

Pain is the defining feature: widespread (axial skeleton and both sides, above and below the waist), migrating, described as deep, aching, burning or throbbing, present for at least 3 months and unexplained by any single structural lesion. Patients say "it feels like I have the flu all the time". It is amplified by poor sleep, stress, cold and inactivity, and partly eased by gentle movement and warmth.[1]

Fatigue is often profound and frequently more disabling than the pain; it is not relieved by rest, reflecting disordered non-restorative sleep. Unrefreshing sleep is near-universal — patients wake repeatedly, never reach deep sleep, and feel more tired in the morning. Cognitive dysfunction ("fibro-fog") impairs attention, working memory and word-finding, a major limitation for working patients.[1]

Somatic co-symptoms abound, all reflecting the same central sensitisation: irritable bowel, tension or migraine headache, dysmenorrhoea and pelvic pain, temporomandibular jaw pain, interstitial cystitis, and non-dermatomal paraesthesiae. Several of these in one patient is itself a clue to a central sensitisation syndrome.[1]

The examination is essentially normal apart from tenderness to firm but non-damaging pressure at multiple soft-tissue sites. There is no joint swelling, warmth or synovitis, no muscle wasting or true weakness, no neurological deficit, no sensory level, no organomegaly and no rash. Documenting the absence of these explicitly is part of the assessment — it reassures the patient and anchors the positive diagnosis.[1]

Exclude the mimics — then make a positive diagnosis

The strategy is not to "test for fibromyalgia" but to run a focused baseline panel that excludes the common and treatable mimics, then make a confident positive diagnosis.[1]

[1]

A focused baseline panel suffices for most patients: full blood count, ESR and CRP, renal and liver function, creatine kinase, TSH, vitamin D and calcium. Autoantibodies (ANA, RF, anti-CCP) are requested only when clinical features suggest an inflammatory connective-tissue disease — a low-titre ANA is common in healthy people, non-specific, and must not by itself trigger a cascade of further testing. Imaging is obtained only to evaluate a specific local symptom or a red flag, never to "screen" a fibromyalgia patient.[1]

The pain-to-synovitis mismatch — the overlap trap

Fibromyalgia overlaps with inflammatory rheumatic disease in 20 to 30 percent of patients with rheumatoid arthritis, SLE or spondyloarthritis — and this is the most clinically important scenario in the topic.[1]

The nociplastic pain inflates composite disease-activity scores — DAS28 in RA, SLEDAI in SLE, BASDAI in ankylosing spondylitis — through the tender-joint and patient-global components, so the score overstates true inflammatory activity. The result is the recurring error of escalating immunosuppression that brings no benefit and only adds toxicity.[1]

Red flags — what fibromyalgia never causes

In any patient with known or suspected fibromyalgia, the following features demand targeted investigation for organic disease — none is explained by fibromyalgia itself. This list is the safety net that stops a fibromyalgia label from blinding you to real illness.[1]

• Weight loss, fever, night pain or night sweats — infection or malignancy.
• Markedly raised inflammatory markers (ESR, CRP) — inflammatory rheumatic disease, infection, malignancy; primary fibromyalgia has normal markers.
• Joint swelling, synovitis, prolonged morning stiffness over 1 hour — inflammatory arthritis.
• Neurological deficit, a sensory level, true muscle weakness or a raised CK — neuropathy, myelopathy, myositis.
• New, focal or progressive symptoms — investigate the new problem; do not assume it is "just the fibromyalgia".
• Escalating opioid use with worsening pain — opioid-induced hyperalgesia; plan a taper.
• Severe, untreated depression or suicidal ideation — psychiatric emergency; treat actively.[1]

Non-pharmacological first — the most effective therapy

Non-pharmacological therapy is first-line and the most effective component of management, endorsed uniformly by the EULAR 2017 recommendations, ACR guidance and NICE. The reason is mechanistic: central sensitisation is sustained and amplified by inactivity, deconditioning, sleep disruption, catastrophising and stress — and these are precisely the targets of education, exercise, CBT and sleep hygiene. No single drug addresses all of them.[2]

Patient education and validation is the first therapeutic act. Explain that the pain is real but reflects a sensitised nervous system rather than tissue damage; that fibromyalgia is not progressive, destructive or life-shortening; and that improvement comes through active self-management rather than passive dependence on medication. Making a positive diagnosis and naming the condition is itself therapeutic — it ends the exhausting diagnostic odyssey. Set realistic expectations: improved function, not zero pain.[2]

Graded aerobic exercise is the single best-evidenced intervention. Low-impact activity — walking, swimming, cycling, water aerobics — is started at a comfortable baseline and progressed slowly ("start low, go slow"), explicitly avoiding the boom-and-bust cycle in which the patient overexerts on a good day and crashes for several days after. The goal is a sustainable daily or near-daily habit. Exercise works because it improves conditioning, sleep, mood and endogenous descending inhibition; CBT and pacing sustain adherence.[2][8]

Cognitive behavioural therapy improves coping, reduces catastrophising and fear-avoidance, addresses unhelpful beliefs about pain and harm, and treats comorbid depression and anxiety — among the most effective interventions for long-term function. Sleep hygiene and stress management (regular schedule, cool dark bedroom, no late caffeine or screens, mindfulness-based stress reduction) and pacing (spreading activity evenly) break the boom-bust pattern.[1]

Multidisciplinary care delivers the best outcomes: rheumatologist (confirm diagnosis, exclude rheumatic disease), physiotherapist (graded exercise), psychologist (CBT), pain specialist, sleep medicine, and a single coordinating clinician — usually the primary-care physician — who prevents duplicated investigation, polypharmacy and contradictory advice. Hydrotherapy, tai chi, yoga and acupuncture are useful adjuncts, not substitutes.[1]

The DAPA trio — drugs chosen by the predominant symptom

Drug therapy is an adjunct, not a replacement, for the non-pharmacological foundation. It is chosen by the predominant symptom, used at the lowest effective dose, titrated slowly, and reviewed periodically. The three first-line classes all share one property — boosting descending serotonergic or noradrenergic inhibition, or dampening excitatory transmission — directly targeting the neurochemical deficit of central sensitisation.[1]

[2]

Serotonin-noradrenaline reuptake inhibitors (SNRIs) — duloxetine 30 to 60 mg daily, titrate to 60 to 120 mg, and milnacipran, titrate to 50 to 100 mg twice daily — help pain, fatigue and mood. Duloxetine is particularly useful when comorbid depression or neuropathic features coexist. Watch for nausea, dry mouth and sweating, and a blood-pressure rise with milnacipran.[6]

Alpha-2-delta calcium-channel ligands — pregabalin, start 75 mg at night and titrate to 150 to 300 mg daily in divided doses, and gabapentin, titrate from 300 mg at night — reduce excitatory neurotransmitter release and are useful where sleep disturbance and anxiety predominate. Dizziness, somnolence, weight gain and peripheral oedema are the main side-effects.[7]

Low-dose tricyclic antidepressants — amitriptyline 10 to 25 mg at night — improve sleep, pain and mood through combined serotonergic and noradrenergic action plus mild sedation, and are commonly used first line where sleep is the dominant problem. Warn of anticholinergic effects (dry mouth, constipation, urinary hesitancy, morning grogginess) and fall risk in the elderly.[2][5]

Combination strategy. Start one agent, titrate slowly over 2 to 4 weeks to a target dose, and assess response at 4 to 8 weeks. If a single drug is inadequate, add a second from a different class (for example duloxetine plus pregabalin) — mindful of serotonin-syndrome risk when combining serotonergic agents. Treat comorbid depression and anxiety actively, and screen for and treat obstructive sleep apnoea.[2]

The drugs that harm — opioids, steroids, immunosuppressants

The two greatest iatrogenic dangers in fibromyalgia are over-investigation and opioid escalation. Neither helps; both harm.[1]

Strong opioids are ineffective for nociplastic pain and cause opioid-induced hyperalgesia — a paradoxical worsening and spreading of pain — plus tolerance, dependence and overdose risk. They are among the most important iatrogenic harms in fibromyalgia. A patient on escalating opioids with worsening pain has opioid-induced hyperalgesia until proven otherwise; the treatment is a structured taper with addiction-medicine support, not a higher dose.[1]

Corticosteroids and immunosuppressants (including biologics) have no role in primary fibromyalgia — there is no inflammation to suppress. Escalating immunosuppression in an overlap patient whose high disease-activity score reflects fibromyalgia rather than active inflammation is the classic error the pain-to-synovitis mismatch exists to prevent. Benzodiazepines disrupt sleep architecture, cause dependence and cognitive impairment, and should be minimised. NSAIDs and paracetamol are ineffective for the core nociplastic pain, though they may help a coexisting nociceptive component such as osteoarthritis.[1]

Prognosis, disposition, and the realistic goal

Fibromyalgia is chronic and fluctuating, and complete cure is uncommon — but meaningful improvement in function, pain and quality of life is achievable for the majority who engage with graded exercise, CBT, sleep management and treatment of comorbid mood disorder. The realistic goal is improved function and reduced impact, not zero pain.[1]

Better outcomes track with engagement in graded exercise and CBT, good social support, preserved baseline function, absence of ongoing opioid use, and effective treatment of comorbid depression and sleep disorders. Poorer outcomes track with severe baseline pain and disability, untreated depression or anxiety, ongoing litigation or work-related injury, low health literacy, passive coping (catastrophising, avoidance), and persistent strong-opioid use.[1]

Disposition — refer to rheumatology for a single focused consultation to confirm the diagnosis and exclude rheumatic disease (not indefinite follow-up), to a pain-management programme for refractory cases, to psychiatry or clinical psychology for comorbid mood disorder and CBT, to physiotherapy for supervised graded exercise, and to sleep medicine for suspected apnoea. The primary-care physician is usually the best single coordinator. Fibromyalgia does not reduce life expectancy and is not progressive or degenerative.[1]

Special populations

The patient with inflammatory rheumatic disease. Distinguish inflammatory from nociplastic pain using the pain-to-synovitis mismatch; treat both components; do not escalate immunosuppression solely for pain; and warn against attributing every new symptom to the rheumatic disease — investigate red flags.[1]

Patients on chronic opioids. Plan a structured opioid taper with addiction-medicine input, replacing opioids with evidence-based fibromyalgia therapy. Expect an initial increase in pain perception as hyperalgesia unmasks, followed by gradual improvement.[1]

The elderly. Differentiate from polymyalgia rheumatica, osteoarthritis and hypothyroidism, all more common with age. Choose sedating drugs (amitriptyline) cautiously because of falls, confusion and anticholinergic burden; in older patients duloxetine is often preferred.[1]

Pregnancy. Fibromyalgia does not adversely affect pregnancy outcome. Plan analgesia around non-drug measures and paracetamol; avoid strong opioids; continue graded exercise within obstetric limits; attend to sleep and mood. A post-partum flare is common — anticipate and plan support.[1]

Children and adolescents (juvenile fibromyalgia). Emphasise graded aerobic exercise, CBT, sleep hygiene, and maintaining school attendance and social function. The prognosis is generally better than adult-onset, and a multidisciplinary, family-inclusive approach is preferred.[1]

Men. Fibromyalgia is under-diagnosed in men because of its female predominance and the stereotyped presentation; the criteria, mechanism and management are identical.[1]

Evidence and guidelines — and the regional delta

Three major guidance sets codify management. The ACR 2010 and 2016 diagnostic criteria (Wolfe and colleagues) replaced the 1990 tender-point count with the WPI and SSS, and confirmed that a fibromyalgia diagnosis may coexist with other conditions. The EULAR 2017 revised recommendations (Macfarlane et al.) endorse a graded, stepped approach — begin with non-pharmacological measures (education, exercise, CBT) and reserve pharmacotherapy as an adjunct chosen by predominant symptom. Strong opioids and corticosteroids are not recommended.[1][2]

The nociplastic pain concept (IASP 2017; Treede) and the ICD-11 chronic pain classification formally established nociplastic pain as the third mechanistic descriptor alongside nociceptive and neuropathic — embedding fibromyalgia's mechanism into the international taxonomy. Canadian 2012 guidelines and APS guidance similarly support exercise, CBT and selected pharmacotherapy, and caution against opioids.[1]

The mantra, and the drugs by symptom

The mantra: validate the pain, move the body, fix the sleep — and never reach for an opioid.[1][2]

Ward-round test — three stems, thirty seconds each

Stem 1 — the teaching assistant from the top of the topic (answer)

The 42-year-old on escalating oxycodone with two years of widespread pain, unrefreshing sleep, fibro-fog and a folder of normal tests. What is the diagnosis, and what do you change? Model: This is fibromyalgia — central sensitisation (nociplastic) pain: widespread pain, fatigue, unrefreshing sleep, cognitive dysfunction, normal examination and bloods. Confirm with the ACR 2016 criteria (WPI 7 or more with SSS 5 or more, or WPI 4 to 6 with SSS 9 or more, over 3 months) after a focused baseline panel (FBC, ESR, CRP, CK, TSH, vitamin D) excludes mimics. First-line is non-pharmacological and disease-modifying: education and validation of the pain as real, graded aerobic exercise, CBT, sleep hygiene. Add an adjunct chosen by predominant symptom — duloxetine for mood, pregabalin for sleep and anxiety, low-dose amitriptyline for sleep. Plan a structured opioid taper — her oxycodone is causing opioid-induced hyperalgesia, not helping.[1][2]

Stem 2 — the rheumatoid arthritis patient whose DAS28 keeps rising (answer)

A woman with established rheumatoid arthritis on methotrexate has a rising DAS28, but her CRP is normal, her swollen-joint count is zero, and she is tender everywhere. The registrar proposes adding a biologic. What is the right call? Model: This is the pain-to-synovitis mismatch — a high tender-joint count and high patient-global score (which inflate DAS28) alongside no objective synovitis and a normal CRP. The dominant problem is concomitant fibromyalgia, not an inflammatory flare. The right call is to recognise and treat the central component (graded exercise, CBT, duloxetine or pregabalin), and not to escalate immunosuppression for a score driven by nociplastic pain. Adding a biologic would bring toxicity with no inflammatory target.[1]

Stem 3 — the red flag inside the label (answer)

A patient with well-established fibromyalgia presents with new weight loss, night sweats and a raised ESR. The team attributes it to "a flare". What is the error, and what do you do? Model: Fibromyalgia never causes weight loss, night sweats or a raised ESR. These are red flags demanding targeted investigation for organic disease — infection, inflammatory rheumatic disease, or malignancy (including myeloma). The error is letting a fibromyalgia label blind you to real illness. Investigate: repeat ESR and CRP, blood count, film, protein electrophoresis, and image as guided by the clinical picture. The fibromyalgia is treated in parallel, but the new symptoms are a separate problem until shown otherwise.[1]

References

1. [1]Murphy AE, Minhas D, Clauw DJ. Identifying and Managing Nociplastic Pain in Individuals With Rheumatic Diseases: A Narrative Review Arthritis Care Res (Hoboken), 2023.PMID 36785994
2. [2]Macfarlane GJ, Kronisch C, Dean LE, et al. EULAR revised recommendations for the management of fibromyalgia Ann Rheum Dis, 2017.PMID 27377815
3. [3]Wolfe F, Clauw DJ, Fitzcharles MA, et al. 2016 Revisions to the 2010/2011 fibromyalgia diagnostic criteria Semin Arthritis Rheum, 2016.PMID 27916278
4. [4]Wolfe F, Smythe HA, Yunus MB, et al. The American College of Rheumatology 1990 Criteria for the Classification of Fibromyalgia. Report of the Multicenter Criteria Committee Arthritis Rheum, 1990.PMID 2306288
5. [5]Moore RA, Derry S, Aldington D, et al. Amitriptyline for fibromyalgia in adults Cochrane Database Syst Rev, 2019.PMID 35658166
6. [6]Welsch P, Üçeyler N, Klose P, et al. Serotonin and noradrenaline reuptake inhibitors (SNRIs) for fibromyalgia Cochrane Database Syst Rev, 2018.PMID 29489029
7. [7]Derry S, Cording M, Wiffen PJ, et al. Pregabalin for pain in fibromyalgia in adults Cochrane Database Syst Rev, 2016.PMID 27684492
8. [8]Kim SY, Busch AJ, Overend TJ, et al. Flexibility exercise training for adults with fibromyalgia Cochrane Database Syst Rev, 2019.PMID 31476271