Is It MPS or Fibromyalgia? Understanding the Difference

Because both Myofascial Pain Syndrome (MPS) and Fibromyalgia (FM) involve muscle pain and have no clear “test” like an X-ray, they are frequently confused. While MPS is typically a regional problem, meaning it stays in one part of the body like the neck or the lower back ^[1], fibromyalgia is typically a widespread pain syndrome that affects multiple body regions and is often accompanied by a cluster of other symptoms ^[2][3].

However, the line between them is not absolute. While MPS involves local “knots” in the muscle (trigger points), fibromyalgia is considered a nociplastic pain condition—a state where the brain and spinal cord become oversensitive to all signals, turning up the “volume” on pain across the system ^[4].

The 2016 Fibromyalgia Criteria

In 2016, the American College of Rheumatology (ACR) updated the classification standards for fibromyalgia ^[2]. These criteria are intended for clinical assessment by a healthcare provider, not as a self-diagnosis tool. To meet these criteria, a clinician calculates scores using the Widespread Pain Index (WPI) and the Symptom Severity Scale (SSS) to ensure a patient generally has:

1. Widespread Pain: Pain in at least 4 out of 5 body regions ^[5].
2. Symptom Severity: Significant issues with fatigue, waking up unrefreshed (sleep problems), and cognitive difficulties (often called “fibro fog”) ^[2][6].
3. Persistence: Symptoms that have been present at a similar level for at least three months ^[7].

Can You Have Both?

Yes. It is possible—and common—for MPS and fibromyalgia to coexist ^[4][3]. A person may have the generalized sensitivity and fatigue of fibromyalgia, but also have specific “hot spots” of myofascial trigger points. In these cases, doctors must individualize treatment to address both the “central” sensitivity and the “peripheral” trigger points ^[4].

Other “Look-Alikes”

Before confirming MPS, your doctor may need to rule out other conditions that mimic muscle knots. The absence of an MPS test does not mean blood tests or imaging are unnecessary when an alternative diagnosis is suspected:

• Radiculopathy (Pinched Nerve): While MPS causes referred pain, radiculopathy causes pain that often follows a specific nerve “stripe” (dermatome) and may be paired with true numbness or loss of reflexes ^[8].
• Osteoarthritis: This is a joint problem, not a muscle problem. If your pain is strictly related to moving a specific joint (like the hip or knee) and the joint feels stiff or “gritty,” it may be arthritis rather than a muscle knot ^[9].
• Inflammatory or Infectious Disease: Conditions like polymyalgia rheumatica, inflammatory myopathies, or endocrine/metabolic disorders can cause severe muscle aching and usually require blood tests to identify.
• Medication-Related Myopathy: Certain drugs, such as statins used for cholesterol, can cause muscle aches as a side effect.
• Delayed Onset Muscle Soreness (DOMS): This is the familiar ache that happens 24–72 hours after intense or new exercise ^[10]. Unlike MPS, DOMS usually resolves on its own within a few days ^[10].

By carefully checking for these signs, your medical team can ensure you receive the right treatment for the right source of pain.