Differences Between Fibromyalgia and Myalgic Encephalitis/Chronic Fatigue Syndrome
Fibromyalgia (FM) is a chronic pain syndrome that involves widespread muscle pain (myalgias) and joint pain (arthralgias). Fibromyalgia is thought to be due to a dysfunction in the way the brain and spinal cord process painful and non-painful signals, causing pain amplification.
Myalgic encephalitis (ME), also known as chronic fatigue syndrome (CFS), is a condition involving profound fatigue that can’t be explained by another underlying medical condition. ME/CFS worsens with physical exertion and does not improve with rest. Several features of FM and ME/CFS overlap, however; they are distinct conditions with different symptoms and causes.
Both myalgic encephalitis/chronic fatigue syndrome and fibromyalgia are diagnoses of exclusion, meaning there are no definitive medical tests that can diagnose either condition. The two conditions share several symptoms:
- Muscle and joint pain
- Cognitive impairment or brain fog
- Depression and anxiety
Characteristics that are more definitive of ME/CFS include the following:
- Fatigue more prominent symptom than pain
- Flu-like symptoms, such as sore throat, night sweats, and chills
- Swollen lymph nodes
- Often triggered by a virus, such as mononucleosis
Characteristics of FM that are not as common with ME/CFS include the following:
- Pain is more debilitating than fatigue. This may include symptoms of allodynia (pain associated with non-painful stimuli) and hyperalgesia (unusually amplified pain).
- Symptoms of fibromyalgia often begin after a trauma, such as a car accident.