Can you have both ME CFS and fibromyalgia?

September 25, 2025 •

5 min read

According to one study published in BMC Neurology, approximately 45% of individuals with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) also meet the criteria for fibromyalgia. Understanding if and how you can have both ME CFS and fibromyalgia is crucial for effective management and improving your quality of life.

Quick Summary

Yes, you can be diagnosed with both ME/CFS and fibromyalgia, as they are distinct but commonly co-occurring conditions with significant symptomatic overlap. While ME/CFS is defined by severe, persistent fatigue and post-exertional malaise (PEM), fibromyalgia's hallmark is widespread pain and heightened pain sensitivity.

Key Points

Comorbidity is Common: It is common to have both ME/CFS and fibromyalgia, with some studies finding a significant percentage of patients with one condition also meet the criteria for the other.
Distinguishing Symptoms: While both cause fatigue and pain, the defining symptom of ME/CFS is Post-Exertional Malaise (PEM), while the hallmark of fibromyalgia is widespread pain and heightened pain sensitivity.
No Definitive Test: Both conditions are diagnosed clinically, based on a patient's symptoms and after ruling out other medical issues, as there are no definitive laboratory tests.
Multi-faceted Management: Treatment for co-occurring ME/CFS and fibromyalgia often involves a multi-pronged approach, including medication, physical therapy tailored to the conditions, and pacing to manage energy levels.
Increased Symptom Severity: Research suggests that having both conditions can lead to greater overall symptom severity and more pronounced functional impairment compared to having ME/CFS alone.
Shared Mechanisms: Ongoing research is exploring the shared underlying biological mechanisms, such as immune system dysfunction and central nervous system abnormalities, which may explain the high rate of comorbidity.
Empowerment Through Knowledge: Educating yourself about both conditions is crucial for effective communication with healthcare providers and developing personalized coping strategies.

Understanding the Complex Overlap of ME/CFS and Fibromyalgia

Many people living with chronic illness find themselves grappling with a constellation of symptoms that seem to defy a single diagnosis. This is particularly true for those with ME/CFS and fibromyalgia, two conditions that share significant symptomatic overlap. While they are recognized as distinct disorders, research indicates a high rate of comorbidity, meaning many people are diagnosed with both. Understanding this relationship is the first step toward effective management.

The Defining Features of ME/CFS

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome is characterized by its signature symptom: severe, debilitating fatigue that is not relieved by rest and significantly impacts a person's ability to engage in pre-illness activities. However, the most critical distinguishing feature is post-exertional malaise (PEM)—a dramatic and disproportionate worsening of symptoms following even minor physical, mental, or emotional exertion. This PEM can trigger a cascade of other symptoms, including:

Unrefreshing sleep
Cognitive dysfunction, or “brain fog,” affecting memory and concentration
Orthostatic intolerance (dizziness upon standing)
Muscle and joint pain
Sore throat and tender lymph nodes

The Hallmarks of Fibromyalgia

Fibromyalgia's primary symptom is chronic, widespread musculoskeletal pain, which can be described as a constant, dull ache. This pain is often accompanied by allodynia (pain from stimuli that don’t normally cause pain) and hyperalgesia (an increased sensitivity to pain). Other common symptoms include:

Fatigue, often secondary to pain and poor sleep
Cognitive difficulties, also known as "fibro fog"
Sleep disturbances, such as waking up feeling unrefreshed
Irritable bowel syndrome (IBS)
Tender points, though these are no longer the primary diagnostic criterion

The Double Diagnosis: Why It Happens

The high rate of co-occurrence, with some studies showing nearly half of ME/CFS patients also meeting the criteria for fibromyalgia, is likely due to overlapping underlying biological mechanisms and symptoms. It is not a case of a patient "faking" their symptoms, but rather a reflection of the complexity of these central nervous system disorders. A patient might first consult a rheumatologist for widespread pain and receive a fibromyalgia diagnosis, while another might see an infectious disease specialist for unrelenting fatigue after a viral illness and be diagnosed with ME/CFS. Eventually, as a comprehensive picture of their symptoms emerges, a doctor may determine that both conditions are present.

Differentiating and Overlapping Symptoms: A Comparison

While there is substantial overlap, some key differences can guide both patients and clinicians. The table below outlines some of the major symptomatic distinctions and overlaps.


Feature	ME/CFS	Fibromyalgia	Overlap in Both	Potential Distinguishing Factor
Defining Symptom	Post-Exertional Malaise (PEM)	Widespread Pain	Fatigue	PEM is unique to ME/CFS.
Fatigue Quality	Extreme, debilitating, and unremitting	Can be severe, often secondary to pain/sleep issues	Both cause significant fatigue	ME/CFS fatigue is characterized by PEM.
Pain Type	Muscle and joint pain	Widespread musculoskeletal pain and tenderness	Both involve pain	Widespread pain is the hallmark of fibromyalgia.
Cognitive Issues	"Brain fog" affecting memory and focus	"Fibro fog" affecting concentration	Both experience cognitive impairment	The focus and nature of the impairment can vary slightly.
Sleep Disturbances	Unrefreshing sleep	Unrefreshing sleep	Both experience non-restorative sleep	The underlying sleep pathology may differ.
Triggering Event	Often linked to a viral illness or other health issues	Can follow physical trauma, surgery, or infection	Both can be triggered by stress or illness	Sudden, flu-like onset is more common in ME/CFS.
Orthostatic Intolerance	Common, causing dizziness or lightheadedness	Can occur, but less a primary feature	Can occur in both	More prevalent and central to ME/CFS diagnosis.

The Challenges of Diagnosing Co-occurring Conditions

Diagnosing ME/CFS and fibromyalgia can be challenging, as both are diagnoses of exclusion, meaning other potential medical conditions must be ruled out first. For patients with both, this process can be even more complex. A thorough medical history, physical examination, and blood work are standard. Sleep studies or other specialized tests may also be required to exclude other causes for symptoms. Since there are no definitive biomarkers for either condition, diagnosis relies heavily on a careful assessment of the patient's reported symptoms and their adherence to established diagnostic criteria.

Management Strategies for the Double Diagnosis

Because there is no cure for either condition, treatment focuses on symptom management. A co-diagnosis often requires a multi-pronged approach that addresses both sets of symptoms. While there are some differences, many strategies overlap:

Pacing: Crucial for managing ME/CFS, pacing involves balancing rest and activity to avoid triggering PEM. This is also beneficial for fibromyalgia, as overexertion can exacerbate pain. For patients with both, finding the right balance is key to preventing both a fatigue crash and a pain flare. Using a heart rate monitor can be a helpful tool for some.
Medication: Doctors may prescribe different medications to address the primary issues. Fibromyalgia may be treated with FDA-approved drugs like pregabalin (Lyrica), duloxetine (Cymbalta), or milnacipran (Savella). Antidepressants can help with both mood and pain. Pain relievers, sleep aids, and other off-label medications may also be used.
Physical Therapy: A gentle, individualized approach is critical. For ME/CFS, this focuses on maintaining function and avoiding PEM, not vigorous aerobic exercise, which can be harmful. Fibromyalgia can benefit from gentle exercise and stretching to improve flexibility and reduce stiffness.
Counseling and Support: Cognitive behavioral therapy (CBT) and other forms of counseling can help patients develop coping strategies, manage the mental toll of chronic illness, and navigate life with limiting conditions. Chronic illness can also be isolating, and connecting with support groups can provide valuable emotional support.
Diet and Supplements: While no diet or supplement is a cure, many patients find that dietary adjustments or nutritional supplements can help manage symptoms. It is important to work with a healthcare provider to ensure supplements are safe and appropriate.

The Prognosis of Co-occurring Conditions

Living with both ME/CFS and fibromyalgia presents unique challenges. Research shows that having both conditions may result in greater symptom severity and worse overall functioning compared to having ME/CFS alone. The management of multiple conditions increases healthcare complexity, but a tailored, multi-disciplinary approach can make a significant difference in improving health and quality of life. Regular communication with a healthcare team is vital for adjusting strategies as symptoms and needs change.

Future Directions in Research

Ongoing research continues to explore the underlying biological and neurological connections between ME/CFS and fibromyalgia. Studies into the gut microbiome, immune system activity, and brain imaging are revealing shared pathogenic mechanisms and offering new avenues for diagnosis and treatment. Organizations like the CDC and IACFS/ME continue to push for better research and understanding of these challenging illnesses.

To learn more about effective management strategies, visit the Centers for Disease Control and Prevention resource page on ME/CFS management.

Conclusion

It is entirely possible to be diagnosed with both ME/CFS and fibromyalgia, and in fact, it is a common co-occurrence. While the two conditions are distinct, their shared symptoms and potential underlying biological connections necessitate a comprehensive and individualized approach to management. By understanding the unique defining features of each, patients can work with their healthcare team to create a targeted strategy that addresses both profound fatigue and widespread pain, ultimately aiming for an improved quality of life despite the complex nature of these illnesses.

Frequently Asked Questions

No, while they share many overlapping symptoms, ME/CFS and fibromyalgia are considered distinct conditions. ME/CFS is primarily defined by debilitating fatigue and post-exertional malaise (PEM), whereas fibromyalgia's hallmark is widespread pain and heightened sensitivity to pain.

It is quite common. A study published in BMC Neurology reported that approximately 45% of patients with ME/CFS also had fibromyalgia. This high rate of co-occurrence suggests a strong link between the two conditions.

Yes, research indicates that having both ME/CFS and fibromyalgia can result in more severe symptoms and greater overall functional impairment compared to having only one condition. This often requires a more complex and tailored management approach.

The most significant difference is the defining symptom: Post-Exertional Malaise (PEM) for ME/CFS and widespread pain for fibromyalgia. PEM is a dramatic worsening of symptoms after minor exertion, a feature not central to the diagnosis of fibromyalgia.

Diagnosis for both is clinical, based on a comprehensive evaluation of symptoms, medical history, and ruling out other conditions. There is no specific lab test for either. The diagnosis depends on a patient's specific symptom profile matching the diagnostic criteria for each condition.

Many management strategies can be beneficial for both. For example, pacing and gentle exercise are helpful for managing fatigue and pain in both conditions. However, medications may target different primary symptoms, requiring a multi-faceted treatment plan.

Effective management often involves a holistic and personalized approach. This includes a combination of medication, a carefully calibrated activity plan (pacing), physical therapy, stress reduction, and mental health support. Working with a multidisciplinary team of healthcare professionals is often necessary.