Fibromyalgia is characterised notably by diffuse chronic pain, which may be accompanied by fatigue, sleep disturbances, and other symptoms.
For a woman with fibromyalgia, one question can become particularly difficult: is pelvic pain or very painful periods related to fibromyalgia, or does a gynaecological condition exist alongside it?
The answer is not always simple. Research suggests overlaps between fibromyalgia and several chronic pain syndromes. Some studies have also observed more menstrual or gynaecological symptoms in populations with fibromyalgia.
But these associations do not allow us to state that gynaecological pain is "caused by fibromyalgia". Pelvic pain, debilitating periods, pain during intercourse, or unusual bleeding must therefore be evaluated in their own right.
Fibromyalgia and pain sensitisation
Fibromyalgia is a complex chronic pain syndrome. Its exact mechanisms are not fully understood.
Central sensitisation is among the mechanisms studied. It refers to a change in how the central nervous system processes pain signals, which may contribute to amplification or persistence of pain.
A systematic review of brain imaging studies found moderate evidence in favour of alterations in networks involved in pain perception and modulation in people with fibromyalgia, while noting that the cause-and-effect relationships remain to be clarified.
Central sensitisation mechanisms are also studied in certain chronic pelvic pain conditions.
This does not, however, mean that pelvic pain in a woman with fibromyalgia would be "purely neurological", or that it would be pointless to look for a gynaecological cause.
Can fibromyalgia be associated with pelvic pain?
Yes, pelvic symptoms can coexist with fibromyalgia.
A systematic review devoted to pelvic floor disorders in people with fibromyalgia found data suggesting a significant frequency of gastrointestinal, genito-urinary, and gynaecological symptoms. The authors noted, however, that the small number of studies and their heterogeneity prevented precise quantification of the prevalence.
A distinction must therefore be made between coexistence and causality: observing two conditions in the same patient does not prove that one causes the other.
Why should pelvic pain not be automatically attributed to fibromyalgia?
Because pelvic pain can have many causes.
Among the possible gynaecological diagnoses are notably:
- endometriosis;
- adenomyosis;
- an ovarian cyst;
- a fibroid;
- a gynaecological infection;
- certain vulvar pain conditions;
- pelvic floor disorders.
Urinary, digestive, musculoskeletal, or neurological causes are also possible.
A woman already diagnosed with fibromyalgia can therefore independently develop a gynaecological condition. Attributing new pain too quickly to fibromyalgia could delay another diagnosis.
Fibromyalgia and painful periods: what do the studies show?
Some studies have observed more dysmenorrhoea in women with fibromyalgia.
A case-control study involving 98 patients with fibromyalgia and 102 controls reported primary dysmenorrhoea in 41% of patients with fibromyalgia versus 28% of controls. Premenstrual syndrome was reported in 42% of patients with fibromyalgia versus 25% of controls.
These results show an association within the population studied. They do not demonstrate that fibromyalgia causes dysmenorrhoea, and these figures should not be generalised to all women.
Can periods worsen fibromyalgia symptoms?
Some patients report variations in their symptoms over the course of the cycle.
In a study involving 80 premenopausal women with fibromyalgia, 45% reported an increase in pain and 57.5% an increase in fatigue during periods. A subgroup who kept a diary for one cycle also showed variations in pain and fatigue scores according to cycle phase.
This study is nevertheless old, of limited size, and partly based on reported symptoms. It would therefore be excessive to state that menstruation necessarily worsens fibromyalgia in all women.
Fibromyalgia and hormones: what do we really know?
The possible role of sex hormones in modulating symptoms has been studied. However, the relationships between hormones, the nervous system, sleep, stress, and pain perception are complex.
To date, it would be reductive to present fibromyalgia as simply a "hormonal" condition.
Similarly, a variation in symptoms around periods does not prove the existence of a gynaecological hormonal disorder.
Fibromyalgia and menopause
Variations in symptoms have also been reported around menopause. In the study by Pamuk and Cakir, some women reported the onset or worsening of symptoms around this time.
This observational data does not demonstrate that menopause directly causes or worsens fibromyalgia.
A worsening of pain, fatigue, or sleep disturbances in perimenopause therefore deserves a comprehensive assessment rather than automatic attribution to a single hormonal cause.
Is there a link between fibromyalgia and endometriosis?
Several studies have explored their coexistence, but the results do not establish a simple causal link.
A large cross-sectional study from an Israeli healthcare database identified women with both diagnoses simultaneously and described an association between endometriosis, fibromyalgia, and certain other comorbidities.
Conversely, a Brazilian study comparing 257 women with surgically and histologically confirmed endometriosis to 253 women without endometriosis found no difference in the prevalence of fibromyalgia according to the ACR 2010 criteria.
These results illustrate why caution is necessary: an association is observed in some populations, but it is neither uniform nor proof that one condition causes the other.
Could endometriosis be mistaken for fibromyalgia?
The two conditions are different.
Endometriosis is a gynaecological condition characterised by the presence of tissue similar to the endometrium outside the uterine cavity. Fibromyalgia is a widespread chronic pain syndrome.
Some manifestations may nevertheless overlap: chronic pain, fatigue, sleep disturbances, and impaired quality of life.
In a patient with fibromyalgia, very painful periods, cyclical pelvic pain, pain during intercourse, pain on defecation linked to the cycle, or other suggestive symptoms warrant appropriate gynaecological assessment.
Can there be both a gynaecological cause and pain amplification?
Yes.
A peripheral condition can be a source of pain while, at the same time, sensitisation mechanisms of the nervous system contribute to the intensity or persistence of symptoms.
A systematic review on chronic urogynaecological pelvic pain found evidence supporting the involvement of central sensitisation in several pelvic pain syndromes.
It should therefore not be artificially assumed that "a lesion exists" is opposed to "the nervous system is involved in the pain". These mechanisms can coexist.
Why can pain persist after treatment of a gynaecological cause?
When pain becomes chronic, several mechanisms can contribute to its persistence:
- several simultaneous pain generators;
- hypertonia or myofascial pain of the pelvic floor;
- sensitisation of the nervous system;
- another associated painful condition;
- factors such as sleep and fatigue that can modulate the pain experience.
The persistence of pain therefore requires re-assessment rather than an automatic conclusion.
Does a normal ultrasound mean the pain comes from fibromyalgia?
No.
A normal pelvic ultrasound does not rule out all causes of pelvic pain and does not demonstrate that the pain comes from fibromyalgia.
The diagnosis relies on the clinical history, symptoms, examination and, when indicated, further investigations.
When should you consult a gynaecologist if you have fibromyalgia?
A consultation is particularly relevant in the presence of:
- new pelvic pain;
- periods that have become very painful or debilitating;
- pain during intercourse;
- unusual or very heavy bleeding;
- clearly cyclical pain;
- persistent vulvar symptoms;
- urinary or digestive symptoms linked to the cycle;
- difficulty conceiving associated with gynaecological symptoms;
- any unusual change that does not fit the usual pattern of pain.
A prior diagnosis of fibromyalgia should not prevent a gynaecological cause from being investigated when it is plausible.
Can a multidisciplinary approach be helpful?
Yes, when several pain mechanisms are involved.
Depending on the situation, management may involve a gynaecologist, general practitioner, the professional overseeing fibromyalgia follow-up, a pain specialist, and a physiotherapist trained in the pelvic floor when there is an indication.
The aim is not to multiply investigations, but to identify the different factors contributing to the pain and organise a coherent strategy.
Key points to remember
Fibromyalgia and gynaecological pain can coexist, but they should not be confused.
Some studies suggest more dysmenorrhoea, pelvic symptoms, and variations in pain over the course of the cycle in women with fibromyalgia. The evidence nevertheless remains heterogeneous and does not demonstrate a simple causal relationship.
Endometriosis and fibromyalgia can also be diagnosed in the same patient, but the literature does not support the claim that one causes the other.
Central sensitisation helps to understand certain chronic pain mechanisms, but it should never be used to dismiss a gynaecological cause too quickly.
A woman with fibromyalgia can also develop a gynaecological condition. Any new, cyclical, debilitating, or unusual pain therefore deserves to be evaluated in its own right.
Medical information: this article provides general information and does not replace a consultation. Sudden or intense pelvic pain, feeling faint, high fever, heavy bleeding, or pain associated with a possible pregnancy may require prompt medical assessment.
Scientific Sources
Kaya S, Hermans L, Willems T, Roussel N, Meeus M. Central sensitization in urogynecological chronic pelvic pain: a systematic literature review. Pain Physician. 2013;16(4):291-308. PMID: 23877446. https://pubmed.ncbi.nlm.nih.gov/23877446/
Cagnie B, Coppieters I, Denecker S, et al. Central sensitization in fibromyalgia? A systematic review on structural and functional brain MRI. Semin Arthritis Rheum. 2014;44(1):68-75. PMID: 24508406. https://pubmed.ncbi.nlm.nih.gov/24508406/
Pamuk ON, Cakir N. The variation in chronic widespread pain and other symptoms in fibromyalgia patients. The effects of menses and menopause. Clin Exp Rheumatol. 2005;23(6):778-782. PMID: 16396694. https://pubmed.ncbi.nlm.nih.gov/16396694/
Evaluating the relation of premenstrual syndrome and primary dysmenorrhea in women diagnosed with fibromyalgia. PMID: 25772663. https://pubmed.ncbi.nlm.nih.gov/25772663/
Prevalence of Pelvic Floor Disorders in the Fibromyalgia Population: A Systematic Review. PMID: 31320239. https://pubmed.ncbi.nlm.nih.gov/31320239/
Nunes FR, Ferreira JM, Bahamondes L. Prevalence of fibromyalgia and quality of life in women with and without endometriosis. Gynecol Endocrinol. 2014;30(4):307-310. PMID: 24410333. https://pubmed.ncbi.nlm.nih.gov/24410333/
Evidence for an association between endometriosis, fibromyalgia, and autoimmune diseases. PMID: 30682223. https://pubmed.ncbi.nlm.nih.gov/30682223/
Consult Dr. Yasmine Maazouzi at the Hôpital Privé Beauregard (23 Rue des Linots, Bât. B5 ICOGM, Marseille 13004) for a gynaecological assessment tailored to your situation.