Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a serious, long-term illness that affects many body systems. People with ME/CFS are often not able to do their usual activities. At times, ME/CFS may confine them to bed. People with ME/CFS have severe fatigue and sleep problems. ME/CFS may get worse after people with the illness try to do as much as they want or need to do. This symptom is called post-exertional malaise (PEM). Other symptoms can include problems with thinking and concentrating, pain, and dizziness.
According to an Institute of Medicine (IOM) report, an estimated 836,000 to 2.5 million Americans suffer from ME/CFS. However, most of them have not been diagnosed.
ME/CFS and COVID-19: What we know
CDC is working with partners and stakeholders to better understand post-COVID conditions and how they affect people with ME/CFS. Currently, there are limited data and information about the long-term effects of COVID-19. A recent report found that COVID-19 can result in prolonged illness, even among adults without underlying chronic medical conditions. Future studies will help identify whether some people with delayed recovery develop an ME/CFS-like illness.
It is especially important for people at increased risk of severe illness from COVID-19 to protect themselves. Currently, ME/CFS is not included in the list of medical conditions that increase risk of severe illness from COVID-19. However, people with ME/CFS might consider taking extra precautions to reduce their risk of getting COVID-19. We are learning more about COVID-19 every day. As new information becomes available, CDC will continue to update our recommendations and guidance.
Medscape Continuing Medical Education (CME)

CDC has partnered with Medscape to offer five continuing medical education (CME) activities for healthcare providers. All courses can be accessed by either a desktop computer or a mobile device.
- Update on the Clinical Evaluation and Care of Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome [2 MB, 8 pages] (Author: Benjamin Natelson, MD)
- A Fresh Look at Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Diagnosis and Management of a Multisystem Illness (Authors: Benjamin Natelson, MD; Donna Felsenstein, MD; Mitchell Miglis, MD; Dale Strasser, MD)
- ME/CFS: A Case-Based Learning Module (Author: Stephen Gluckman, MD)
- ME/CFS: Test Your Strengths and Gaps in Knowledge (Author: Nancy Klimas, MD)
- Diagnosing Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: The Experts Weigh In (Authors: Lucinda Bateman, MD; Natalie Azar, MD; Nancy Klimas, MD; José Montoya, MD; Valid for credit through: 3/17/2022)
Related Resources
- ME/CFS and Long COVID: Q&A With the CDC’s Dr Jennifer Cope
- Beyond Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Redefining an Illness
- NINDS/CDC Common Data Elements (CDEs) for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)
- Disability and ME/CFS
- ME/CFS: Making strides to enhance the lives of those living with ME/CFS
- Our Global Voices: CDC Team Takes ME/CFS Around the Word
- NIH Director’s Blog: Moving Toward Answers in ME/CFS, March 2017
- NIH ME/CFS website
- CFS Advisory Committee to HHS
- FDA Voice of the Patient [267 KB, 23 pages]
- ME/CFS clinical trials
- Podcast: ME/CFS: Better Understanding of a Complex Illness