Is Fever a Common Symptom of Fibromyalgia?

Fever is not considered a common or defining symptom of fibromyalgia. Authoritative symptom lists for fibromyalgia emphasize widespread body pain, fatigue, sleep problems, and cognitive difficulties; they do not include fever among typical features. ^{[1] [2]} In standard clinical descriptions, laboratory tests are usually normal, and fever is not expected in straightforward fibromyalgia. ^[3]

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What Fibromyalgia Typically Looks Like

• Core symptoms: widespread musculoskeletal pain, stiffness, fatigue, and sleep disturbance. ^{[1] [2]}
• Other possible symptoms: headaches (including migraines), “fibro fog” (trouble with thinking and concentration), tingling or numbness in extremities, and digestive complaints like irritable bowel syndrome. ^{[1] [2]}

These established symptom sets do not list fever as a routine feature. ^{[1] [2]}

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Evidence on Fever-Like Complaints in Fibromyalgia

While fever is not typical, small studies have observed that a minority of people with fibromyalgia report low‑grade fever or flu‑like episodes, often without objective infection markers:

• In one rheumatology cohort, 28% reported recurrent low‑grade fevers, alongside sore throat and lymph node symptoms, yet Epstein–Barr virus antibody profiles were not different from controls. ^[4]
• Another study found that only 4 of 33 fibromyalgia participants reported fever, suggesting that fever and painful lymph nodes may help distinguish chronic fatigue syndrome from fibromyalgia when present. ^[5]

These findings suggest subjective or intermittent low‑grade fever complaints can occur, but they are uncommon and not part of diagnostic criteria for fibromyalgia. ^[5]

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Why Fever Should Prompt a Re‑Check

Because fibromyalgia is not an inflammatory or infectious disorder in its classic form, new, persistent, or high fevers should raise the possibility of another condition such as infection, autoimmune disease (e.g., rheumatoid arthritis or lupus), medication reactions, or other medical causes and warrant appropriate evaluation. ^{[6] [7]}

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Inflammation Markers and “Low‑Grade” Signals

Most routine inflammatory markers (like ESR and CRP) are typically normal in fibromyalgia; when elevated, clinicians look for other causes. ^[3] Some research shows high‑sensitivity CRP can be modestly higher in a subset of fibromyalgia patients, especially those with higher body mass index, but this does not equate to a classic fever‑driven inflammatory illness. ^[8] In that study, IL‑6 and IL‑8 and ESR were not significantly different from healthy controls, reinforcing that systemic inflammation is not a consistent hallmark of fibromyalgia. ^[8]

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Practical Guidance

• If you live with fibromyalgia and develop a true fever (≥38°C/100.4°F), especially lasting more than a day or two or accompanied by rash, severe cough, chest pain, shortness of breath, or significant swelling, it’s reasonable to contact a clinician to check for infection, autoimmune flare, or other causes. ^{[6] [7]}
• Document your symptoms: note temperature readings, timing, associated symptoms, new medications, and exposure risks to help your clinician differentiate causes. ^[6]
• Remember: fibromyalgia symptom management (pain control, sleep optimization, stress reduction, activity pacing) remains central, but fever is unusual and should not be assumed to be “just fibromyalgia.” ^{[2] [3]}

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Bottom Line

• Fever is not a common symptom of fibromyalgia and is not part of standard diagnostic features. ^{[1] [2]}
• Occasional reports of low‑grade fever occur in a minority of people with fibromyalgia, but these are not typical and should prompt consideration of other diagnoses if persistent or significant. ^{[4] [5]}
• Seek medical evaluation for sustained or high fever to rule out infection, autoimmune disease, medication reaction, or other causes. ^{[6] [7]}