Based on NIH | How common is nausea in fibromyalgia, and what mechanisms or comorbidities are thought to cause it?

Nausea is not a core diagnostic symptom of fibromyalgia, but gastrointestinal (GI) complaints are common in people with fibromyalgia, and nausea can occur as part of that GI symptom cluster. In broad population terms, fibromyalgia itself affects roughly 2%–8% of people worldwide, with higher rates in women and with increasing age, which helps explain why associated symptoms like GI issues are frequently encountered. ^{[1] [2]} GI complaints commonly reported alongside fibromyalgia include abdominal pain, bloating, constipation, and irritable bowel syndrome (IBS), and these can be accompanied by nausea in some individuals. ^{[3] [4]}

How common is nausea in fibromyalgia?

There is limited high-quality, precise prevalence data specifically for “nausea” in fibromyalgia, because most studies group nausea under broader GI symptom categories (such as dyspepsia or functional GI disorders) rather than measuring nausea alone. ^{[5] [6]} What is consistent across studies and clinical guidance is that GI symptoms are frequently comorbid with fibromyalgia particularly IBS and functional dyspepsia which often include nausea among their symptom lists. ^{[4] [6]} Given the high comorbidity of IBS and other functional GI disorders in fibromyalgia, it is reasonable to expect that a meaningful subset of individuals with fibromyalgia experience episodic or chronic nausea, although exact percentages vary across cohorts and are not firmly established. ^{[5] [6]}

Why nausea can occur: key mechanisms

Multiple overlapping mechanisms may contribute to nausea in fibromyalgia. No single cause explains nausea for everyone, and more than one mechanism can be active at the same time. ^{[7] [8]}

• Central sensitization and altered pain processing: Fibromyalgia is characterized by heightened sensitivity to pain and sensory input, which can extend to visceral sensations from the gut; this can amplify discomfort, satiety cues, and dyspeptic sensations that manifest as nausea. ^[7] This altered central processing is a recognized feature of fibromyalgia’s broader symptom profile. ^[9]

• Autonomic nervous system dysregulation (dysautonomia): Autonomic dysfunction has been described in fibromyalgia, with patterns of sympathetic-parasympathetic imbalance that may impair normal gut motility and gastric accommodation; this can lead to symptoms such as early satiety, bloating, and nausea. ^[8] Autonomic dysfunction affecting the digestive tract is known to produce gastroparesis (slow stomach emptying), which causes nausea and vomiting. ^[10]

• Brain–gut axis changes and functional GI overlap: Fibromyalgia commonly coexists with functional GI disorders like IBS and functional dyspepsia; these conditions involve dysregulated communication between the brain and the gut and frequently include nausea as part of their symptom spectrum. ^[6] People with fibromyalgia have higher rates of digestive disorders such as IBS, which underscores this shared pathway. ^[11]

• Dietary sensitivities and microbiome factors: Some reports suggest symptoms may be influenced by sensitivity to gluten, lactose, or fermentable carbohydrates (FODMAPs), and by small intestinal bacterial overgrowth or post-infectious changes, all of which can contribute to dyspepsia and nausea in susceptible individuals. ^[5]

• Sleep disturbance and stress triggers: Sleep problems and stress both common in fibromyalgia can worsen autonomic balance and visceral sensitivity, thereby increasing susceptibility to nausea. ^{[12] [9]}

Common comorbidities linked to nausea

Several conditions that frequently coexist with fibromyalgia are associated with nausea:

• Irritable bowel syndrome (IBS): IBS is commonly comorbid with fibromyalgia and includes abdominal pain, bloating, and altered bowel habits that may be accompanied by nausea, especially during flares. ^{[3] [4]}

• Functional dyspepsia: Often presents with upper abdominal discomfort, early fullness, and nausea; it shares pathophysiology with other functional pain syndromes that overlap with fibromyalgia. ^[6]

• Gastroesophageal reflux disease (GERD): Reflux can cause upper GI discomfort and sometimes nausea, and it is noted among other symptoms seen with fibromyalgia. ^[4]

• Autonomic dysfunction and gastroparesis: Dysautonomia can impair gastric emptying (gastroparesis), a well-known cause of nausea and vomiting in affected individuals. ^[10] Autonomic profile abnormalities have been discussed in fibromyalgia, supporting this link. ^[8]

Practical implications

• Symptom framing: Nausea in fibromyalgia is best understood as part of a broader GI and autonomic symptom cluster rather than a standalone hallmark of fibromyalgia. ^{[3] [8]}

• Evaluation: When nausea is persistent or severe, consider assessment for functional GI disorders (IBS, functional dyspepsia), GERD, dietary triggers, and signs of autonomic dysfunction that might suggest impaired motility. ^{[4] [6]} If symptoms suggest delayed gastric emptying (fullness after small meals, vomiting undigested food), evaluation for gastroparesis can be appropriate. ^[10]

• Management approach: Addressing sleep quality, stress, and gentle, regular physical activity can support autonomic balance and may reduce nausea in some people. ^{[12] [8]} Dietary strategies (for example, identifying lactose or FODMAP sensitivities) can also help when food triggers are suspected. ^[5] Treating overlapping conditions like IBS or GERD according to standard care often improves nausea as well. ^[4]

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Quick reference: contributors to nausea in fibromyalgia

Contributor	How it may cause nausea	Notes
Central sensitization	Heightens visceral sensation; amplifies dyspepsia/nausea	Part of fibromyalgia’s altered pain processing profile. [7] [9]
Autonomic dysregulation	Impaired gastric motility and accommodation; possible gastroparesis	Dysautonomia described in fibromyalgia; gastroparesis causes nausea/vomiting. [8] [10]
Functional GI overlap (IBS/dyspepsia)	Brain–gut axis dysregulation leads to nausea during flares	Functional pain syndromes commonly coexist. [6] [4]
Dietary/microbiome factors	Food sensitivities, SIBO, post-infectious changes trigger nausea	Reported in GI component of fibromyalgia. [5]
Sleep and stress	Worsen autonomic balance and visceral sensitivity	Sleep disturbance and stress are common in fibromyalgia. [12] [9]

In summary, while exact prevalence figures for nausea in fibromyalgia are not firmly defined, GI symptoms are common in fibromyalgia and often include nausea, driven by central sensitization, autonomic dysregulation, and overlap with functional GI disorders like IBS and dyspepsia. ^{[3] [6]} Recognizing these mechanisms helps tailor evaluation and management so that nausea is addressed alongside the broader symptom constellation. ^{[7] [8]}