Chronic pain is complex, and two common conditions causing musculoskeletal discomfort are Fibromyalgia (FM) and Myofascial Pain Syndrome (MPS). Both are distinct chronic pain disorders affecting soft tissues, but their overlapping symptoms often confuse patients and providers. An individual can be diagnosed with both FM and MPS simultaneously. Understanding why they frequently co-occur is crucial for developing an effective, targeted management strategy. This article clarifies the relationship between these syndromes and explains the necessary combined approach to diagnosis and treatment.
Differentiating Fibromyalgia and Myofascial Pain Syndrome
Fibromyalgia is understood to be a centralized pain sensitization disorder, meaning the condition arises from how the central nervous system processes pain signals. The brain and spinal cord amplify sensory input, leading to a heightened sensitivity to pain known as hyperalgesia and allodynia. This results in pain that is widespread, diffuse, and often migratory, affecting multiple areas both above and below the waist. FM pain is accompanied by a host of systemic symptoms, including persistent fatigue, non-restorative sleep, and cognitive difficulties often referred to as “fibro fog.”
In contrast, Myofascial Pain Syndrome is considered a peripheral pain disorder, originating from localized problems within a specific muscle or muscle group. The defining feature of MPS is the presence of a trigger point (TrP), which is a hyperirritable spot within a taut band of skeletal muscle. These trigger points often develop due to muscle trauma, overuse, or chronic strain, creating a palpable knot within the muscle fiber. Unlike the diffuse tenderness of FM, the pain from a trigger point is regional and can be felt as a deep, aching muscle pain.
The clinical difference lies in the nature of the tender spots. FM is characterized by tender points (TePs), which are areas of generalized soreness that do not refer pain to other sites, and a knot cannot be felt. MPS is defined by trigger points (TrPs), which are true muscular knots that, when pressed, can elicit a twitch response or refer pain to a distant, predictable area of the body.
The Overlap: Why Co-occurrence is Common
Fibromyalgia and Myofascial Pain Syndrome frequently coexist, with studies suggesting that nearly a quarter of MPS patients may also meet the criteria for FM. This common co-occurrence is explained by the biological connection between the peripheral (localized) and central (systemic) nervous systems.
The localized pain from active trigger points in MPS provides a continuous stream of pain signals to the central nervous system. This persistent peripheral input drives central sensitization, fueling the hyper-responsive state that defines FM. If MPS is left untreated, chronic pain signals can lead to the development or exacerbation of widespread pain and systemic symptoms. Centralized sensitization from FM can also lower the pain threshold, making muscles more susceptible to forming new trigger points.
The presence of both conditions presents a diagnostic challenge, requiring a clinician to distinguish carefully between the two types of pain. Widespread pain may be a combination of systemic sensitization from FM and referred pain patterns generated by active trigger points from MPS. Pinpointing the specific, palpable, and pain-referring trigger points allows the provider to address the localized muscular component of the pain. Recognizing both diagnoses ensures the entire spectrum of the patient’s pain is addressed, rather than just the generalized symptoms.
Navigating Diagnosis and Combined Treatment
Diagnosing both conditions relies on a detailed patient history and a physical examination to identify characteristic pain points. The clinical assessment must differentiate between the generalized tenderness of FM and the specific, localized, pain-referring nature of MPS trigger points. Once a dual diagnosis is established, management requires a multimodal approach addressing the unique pathology of each syndrome simultaneously.
Treatment for Fibromyalgia focuses on managing systemic central sensitization, involving pharmacological and non-pharmacological interventions. Medications often target the central nervous system, including certain antidepressants and anti-epileptic drugs designed to calm amplified pain signals. Lifestyle modifications, such as regular, gentle exercise, cognitive behavioral therapy, and strategies for improving sleep hygiene, are important for managing the central symptoms of FM.
The treatment plan for Myofascial Pain Syndrome focuses on localized, mechanical interventions aimed at deactivating the trigger points. These peripheral therapies include physical therapy, specialized massage techniques, and stretching to release the taut muscle bands. Highly localized treatments, such as dry needling or trigger point injections, directly address the source of the regional pain. Effective management of co-occurring conditions requires therapies for the central pain (FM) to work alongside therapies for the peripheral pain (MPS) for comprehensive relief.