Understanding fibromyalgia — together
A short, interactive walk through what someone you love actually lives with when they have fibromyalgia — and how to show up for them. Earn empathy points, unlock ally badges, and finish as a certified Fibro Ally.
- 1Why the pain is real — even when every test comes back normal
- 2What "limited energy" feels like, hands-on
- 3The words that help — and the ones that quietly hurt
The volume is turned up
Fibromyalgia isn't damage where it hurts. The nervous system amplifies pain signals — a process called central sensitization. The brain and spinal cord turn the "volume" of pain up, so ordinary sensations can register as painful.
Pathophysiology: Why Standard Tests Are Negative
Fibromyalgia is not a peripheral tissue disease — it is a disorder of central pain processing. Standard investigations (CRP, ESR, ANA, imaging) are negative because the pathology is neurological, not structural. fMRI studies demonstrate that FM patients show heightened activation of pain-processing regions (anterior insula, S1, ACC) in response to stimuli that produce minimal activation in controls — objective evidence of central amplification, not fabrication.
Key Neurochemical Abnormalities
CSF analysis in FM reveals: Substance P 3× normal (primary nociceptive neurotransmitter); glutamate elevated in insula (excitatory amplification); 5-HIAA reduced (serotonin metabolite — descending inhibition deficient); BDNF upregulated spinally (promotes synaptic potentiation / wind-up). These findings are reproducible and published across multiple independent cohorts.
2016 ACR Diagnostic Criteria (Clinical Application)
Diagnosis requires: WPI ≥ 7 + SSS ≥ 5, or WPI 4–6 + SSS ≥ 9; symptoms present ≥ 3 months; no alternative explanation. The widespread pain index (WPI) counts 19 body regions; the symptom severity score (SSS) rates fatigue, unrefreshed sleep, and cognitive symptoms 0–3 each, plus somatic symptom burden. Tender point examination is no longer required and was abandoned due to poor inter-rater reliability.
Yunus MB (2015). Editorial review: An update on central sensitivity syndromes. Curr Rheumatol Rev 11(2):70-77.
Wolfe F et al. (2016). 2016 Revisions to the 2010/2011 fibromyalgia diagnostic criteria. Semin Arthritis Rheum 46(3):319-329.
Looks fine. Isn't fine.
Someone with fibromyalgia can look completely well while managing severe pain, fatigue and fog. "But you don't look sick" is one of the hardest things to hear.
Small Fibre Neuropathy — The Histological Finding
Skin punch biopsy studies consistently show reduced intraepidermal nerve fibre density (IENFD) in 40–55% of FM patients, providing objective histological evidence of peripheral nerve pathology contributing to central sensitisation. This finding supports FM as a mixed central-peripheral condition in a subset of patients, and has implications for treatment selection (alpha-lipoic acid, IVIG in SFN-positive subgroup).
Autonomic Nervous System Markers
Heart rate variability (HRV) is consistently reduced in FM — specifically, reduced high-frequency HRV (parasympathetic index) and elevated LF/HF ratio (sympathetic dominance). This is measurable with wearable devices and provides a trackable biomarker for treatment response. Orthostatic testing frequently reveals POTS-like haemodynamic responses — relevant to medication selection (avoid alpha-1 blockers; consider low-dose beta-blockade or ivabradine in tachycardic subgroup).
Neuroimaging Findings (Research Context)
Inflammatory Markers — What Elevated and What Isn't
Classic inflammatory markers (CRP, ESR, IL-6) are normal in uncomplicated FM. However, IL-8 (CXCL8) and IL-1β are elevated in CSF and in some peripheral blood studies. Serum IL-8 is emerging as a potential response biomarker for exercise and aquatic therapy interventions. Not yet clinically available as a validated test but relevant for research documentation.
Caro XJ, Winter EF (2014). Evidence and proposed mechanisms of central sensitization in FM. Curr Pain Headache Rep 18(4):411.
Julien N et al. (2005). Widespread pain in FM is related to a deficit of endogenous pain inhibition. Pain 114(1-2):295-302.
Why yesterday doesn't predict today
Symptoms swing — sometimes hour to hour. A good morning doesn't promise a good afternoon. A last-minute cancellation is the illness talking, not flakiness. Tap through a real-feeling week.
Why Symptoms Fluctuate: Allostatic Load Model
FM symptom fluctuation is not random — it reflects allostatic load: the cumulative physiological cost of maintaining homeostasis under chronic central sensitisation. Any stressor (physical exertion, cognitive load, sleep disruption, emotional stress, infection, barometric change) consumes allostatic reserve. When reserve is depleted, pain amplification thresholds drop and symptoms surge. The "good morning, bad afternoon" pattern reflects a patient who has exhausted their daily allostatic reserve in the first half of the day.
Post-Exertional Malaise in FM vs. ME/CFS
FM with PEM (estimated 20–40% of FM patients): Exertion triggers immune activation (NK cell dysfunction, cytokine surge), oxidative phosphorylation impairment, and symptom worsening lasting 24–72+ hours. GET is contraindicated. Pacing and heart rate-guided activity management required. These patients often have overlapping ME/CFS or MCAS.
Anaerobic Threshold in FM — Clinical Significance
Cardiopulmonary exercise testing (CPET) in FM + PEM patients reveals reduced anaerobic threshold (AT) — often 50–60% of predicted VO₂ max — and critically, an abnormal response on repeat testing (day 2 CPET): AT drops further on day 2, providing objective evidence of post-exertional physiological impairment. This CPET finding is the most objective biomarker for PEM and has implications for disability documentation.
Heart Rate-Guided Pacing Protocol
For PEM-positive FM patients, prescribe activity within the aerobic energy envelope: HR ceiling = 0.6 × (220 − age) as a conservative AT proxy. Activity above this ceiling risks triggering exertional PEM. Wearable HRV monitoring (Apple Watch, Garmin) enables real-time AT boundary awareness — a practical clinical tool for self-management.
VanNess JM et al. (2010). Cardiopulmonary symptoms and ST-segment changes with exercise in FM. J Musculoskeletal Pain 18:359-368.
Stussman B et al. (2020). Characterisation of post-exertional malaise in ME/CFS. Front Neurol 11:1025.
A day on a limited battery
Many people describe fibromyalgia using spoons — a way to picture limited energy. You start the day with 12. Every task costs some. When they run out, they're gone — and rest doesn't always refill them. Spend your day.
Mitochondrial Dysfunction in FM
Muscle biopsy and metabolomics studies reveal consistent mitochondrial abnormalities in FM: reduced Complex I and Complex II activity in electron transport chain; elevated ROS (reactive oxygen species); reduced ATP production capacity. This creates a genuine bioenergetic deficit — FM patients produce less ATP per unit of substrate than controls, explaining why ordinary activities consume a disproportionate fraction of their energy reserve.
Autonomic-Metabolic Coupling
FM's sympathetic hyperactivation chronically elevates catecholamines, which increase basal metabolic demand without proportional ATP production capacity. The result: FM patients are effectively running their metabolic engine at a higher idle while producing less power — depleting their "tank" faster. This is the physiological substrate of spoon theory.
Cognitive Energy Depletion — Fibro-Fog Mechanism
The brain consumes ~20% of total body energy at rest. In FM with mitochondrial compromise, cognitive tasks accelerate energy depletion. fMRI during cognitive tasks shows FM patients recruit additional cortical regions compared to controls — achieving equivalent performance at significantly higher neurological cost. This is the mechanistic basis of cognitive fatigue and post-task crashes following mental exertion.
Meeus M et al. (2013). Mitochondrial dysfunction and reduced coenzyme Q10 in FM. Open Access Rheumatol 5:1-7.
Žarković N (2022). Oxidative stress in fibromyalgia — mechanistic review. Antioxidants 11(7):1280.
More than tired
Four things supporters most often underestimate. Tap each card to turn it over.
Say this, not that
For each response, choose whether it helps or hurts. You'll see why after each one.