The Link Between Long COVID and Chronic Fatigue Syndrome (CFS)

Growing attention to Long COVID is sparking renewed interest in Chronic Fatigue Syndrome (CFS), also known as Myalgic Encephalitis (ME). Our COVID Experts Weigh in.

People suffering from Long COVID and Chronic Fatigue Syndrome (CFS) have faced an uphill battle – and not just against their symptoms.

For years, the medical community has been at odds over CFS, leaving patients feeling sidelined. Now, with the emergence of Long COVID, a renewed spotlight has been cast on these ‘mysterious’ conditions, highlighting their similarities and the challenges of their diagnosis. 

Featuring insights from our in-house COVID experts, this post aims to shed light on the striking parallels between these two chronic diseases, emphasizing their shared symptoms and the evolving understanding in the medical community.

Here’s what we’ll cover:

  1. What is Long COVID?
  2. What is Chronic Fatigue Syndrome (CFS)?
  3. Are Symptoms of Long COVID and CFS The Same?
  4. Why are Long COVID and CFS Difficult to Diagnose?
  5. What Research is Being Done to Help People with ME/CFS and Long COVID?

1. What is Long COVID?

Long COVID, sometimes called Long Haul COVID Syndrome (LHCS) or Post-Acute COVID Syndrome, is a prolonged illness that occurs after a COVID-19 infection. It is estimated to affect at least 65 million people around the world.

The symptoms of Long COVID are not limited to the respiratory system. Rather, Long COVID patients are impacted across multiple systems. Long COVID symptoms emerge during the post-infectious period and persist for months and sometimes years.

As we outline in our Long COVID treatment guide, there are several groups of symptoms connected to the syndrome, including:

  • Respiratory
  • Neurological
  • Musculoskeletal
  • Autonomic
  • Gastrointestinal
  • Dermatologic

Patients with Long COVID should be overseen by clinicians familiar with treating this challenging condition. The therapeutic strategy should be tailored based on the grouping of clinical indicators and manifestations.

Since Long COVID is a relatively novel syndrome, patients may have difficulty finding the experienced clinicians they need. For a list of health professionals with Long COVID experience in your area or who offer telehealth, check out our Provider Directory.

Long COVID treatment guide

☝️ Click above to learn more about FLCCC's approach to Long COVID treatment.

2. What is Chronic Fatigue Syndrome (CFS)?

Chronic Fatigue Syndrome (CFS), also known as Myalgic Encephalomyelitis (ME), is a complex and long-term disorder characterized by profound fatigue that isn’t alleviated by rest.

It’s estimated to impact millions globally, though exact numbers vary due to differing diagnostic criteria. Some studies claim up to 91% of people in the United States with myalgic encephalomyelitis remain undiagnosed.

The symptoms of CFS/ME extend beyond just extreme tiredness. Those affected often experience a range of debilitating symptoms that span various bodily systems.

As with Long COVID, CFS/ME encompasses several clusters of symptoms, which include:

  • Cognitive
  • Musculoskeletal
  • Neurological
  • Autonomic
  • Gastrointestinal

As you can see, there are a lot of symptom overlaps between these two illnesses!

Chronic Fatigue Syndrome is often thought to arise from viral infections, notably Epstein-Barr Virus (EBV) and Human Herpesvirus 6 (HHV-6). Given the similarities between CFS and Long COVID, it is