Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Overview

What is chronic fatigue syndrome?

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) or chronic fatigue syndrome (CFS) is a condition that causes you to feel so tired and exhausted that it interferes with your ability to complete your daily routine or even get out of bed. Your fatigue doesn’t improve with rest and gets worse after physical activity or mental exertion. Symptoms usually last for six months or longer.

A healthcare provider may refer to CFS as:

  • Myalgic encephalomyelitis (ME).
  • Systemic exertion intolerance disease (SEID).

How common is chronic fatigue syndrome?

Chronic fatigue syndrome affects an estimated 836,000 to 2.5 million people in the United States. About 90% of people who experience chronic fatigue syndrome don’t receive a diagnosis even though they live with this condition. The main barriers that prevent people from getting a diagnosis are access to healthcare and awareness of the condition.

Symptoms and Causes

What are the symptoms of chronic fatigue syndrome?

Symptoms of chronic fatigue syndrome include:

  • Severe fatigue lasting at least six months that doesn’t improve with rest or sleep.
  • Difficulty sleeping (falling or staying asleep).
  • Headaches.
  • Joint pain.
  • Muscle aches.
  • Difficulty with thinking, attention, concentration and memory.

Other symptoms of CFS include:

For many people, the symptoms of CFS resemble other conditions, like the flu. Symptoms may come and go over time and increase or decrease in severity. CFS symptoms get worse following physical exercise or strenuous mental exertion (post-exertional malaise). Many of the symptoms of CFS make daily life difficult. CFS symptoms vary widely from person to person.

What causes chronic fatigue syndrome?

Healthcare providers don’t know the exact cause of chronic fatigue syndrome. Research suggests there could be several factors that might lead to CFS:

What are the risk factors for chronic fatigue syndrome?

Women and people assigned female at birth are more likely to develop chronic fatigue syndrome than men and people assigned male at birth. Young children and teenagers can develop this condition, but it’s much more common in adults between the ages of 40 and 60.

There may be a genetic link to CFS. Studies found it can run in your biological family history. More research is necessary to determine what gene is responsible for this condition.

What are the complications of chronic fatigue syndrome?

For some people, the fatigue associated with chronic fatigue syndrome makes activities of daily living very difficult or even impossible. Research shows that only half of all people diagnosed with CFS work full-time or part-time jobs.

CFS causes depression. If you experience depression, talk with your healthcare provider. Effective treatments are available.

Diagnosis and Tests

How is chronic fatigue syndrome diagnosed?

A healthcare provider will diagnose chronic fatigue syndrome after a physical exam and mental health evaluation. There isn’t a specific test to diagnose CFS, but tests (like blood or urine tests) help your healthcare provider look for possible causes and rule out conditions with similar symptoms.

The diagnostic criteria for CFS, or the things that your healthcare provider will look for during an exam, include:

  • Severe fatigue that lasts at least six months. Fatigue doesn’t improve with rest or sleep.
  • Difficulty getting restful sleep.
  • Fatigue that gets worse after mental or physical activity.
  • Orthostatic intolerance (inability to sit up without feeling symptoms) and/or problems with cognitive function (thinking and memory).

Management and Treatment

How is chronic fatigue syndrome treated?

Treatment for chronic fatigue syndrome may include:

  • Changes to your sleep routine.
  • Medications.
  • Activity management.

The goal of treatment is to reduce your symptoms so you can regain function in your life. Some people aren’t able to regain the level of health and function they had before their diagnosis.

Sleeping routine changes

Your healthcare provider may recommend the following at-home sleeping habits to improve your rest (sleep hygiene) before prescribing medications or starting other forms of treatment. These may include:

  • Developing a regular bedtime routine, like going to bed and waking up at the same time each day.
  • Not napping for more than 30 minutes total during the day.
  • Using your bed and bedroom only for sleeping and sexual intercourse. Remove all electronics.
  • Avoid eating large meals before you go to bed. Also, avoid alcohol and caffeine before bed.

Medications for chronic fatigue syndrome

A healthcare provider may recommend medications to treat your symptoms:

  • Nonsteroidal anti-inflammatory drugs (NSAIDs) for pain.
  • Antidepressants (tricyclic) for sleep, pain and fatigue.
  • Selective serotonin reuptake inhibitors (SSRI) and serotonin-norepinephrine reuptake inhibitors (SNRI) for depression and pain relief.
  • Antivirals for an infection.
  • Intravenous immunoglobulin (IVIG) to improve how your immune system functions.
  • Corticosteroids for fatigue.

Clinical trials are ongoing to learn more about new medications that can treat your symptoms.

Activity management for chronic fatigue syndrome

Physical activity and mental exertion can make symptoms of fatigue worse. This is post-exertional malaise. A healthcare provider may recommend an activity management practice called pacing to treat this symptom. Pacing balances your rest and activity levels.

When you practice pacing, you learn what your limitations are. Limitations are like a fence. You want to stay within a certain area where it’s safe for your body. Overexertion happens when you step out of the fenced-in area; your body has trouble adjusting to the environment beyond its limits. This can make your symptoms worse.

A healthcare provider will work with you to set your physical and mental limits so you stay within a range that your body can handle. It might help to keep a diary or journal of your activity and symptoms to understand what you do and how it makes you feel. Once you determine your limitations, you’ll need to plan your activities around them to make sure you feel well enough to function.

Exercising or strenuous activity, like aerobic exercises, can make your symptoms worse. Your healthcare provider can help you manage the condition and find physical activities that are safe for you.

Prevention

Can chronic fatigue syndrome be prevented?

Currently, there is no known way to prevent chronic fatigue syndrome.

Outlook / Prognosis

What can I expect if I have chronic fatigue syndrome?

There’s no cure for chronic fatigue syndrome. You may be able to manage symptoms with sleep and activity changes and medications. The goal of treatment is to make symptoms as manageable as possible to increase your quality of life.

Cognitive behavioral therapy is helpful for many people with CFS. This can help you better tolerate symptoms, thoughts and behaviors that may change through treatment.

You’ll have to be careful not to over-extend your activity. Pacing yourself during both mental and physical exertion can help your body recover. Taking breaks and alternating between physical and mental tasks can be helpful.

Your healthcare provider may recommend that you join a support group for people living with CFS. These groups can help you cope with the condition by putting you in touch with others who know exactly what you’re going through.

What’s the outlook for chronic fatigue syndrome?

With treatment, most chronic fatigue syndrome symptoms improve. But some people don’t return to the same health or functional state as they were before their symptoms appeared. The condition affects everyone differently. Talk to your healthcare provider about what your prognosis looks like.

Living With

When should I see a healthcare provider?

If you develop symptoms of chronic fatigue syndrome, especially if your symptoms last six months or longer, contact a healthcare provider. Your provider will evaluate your symptoms and develop a treatment plan to help you feel better.

What questions should I ask my healthcare provider?

  • What type of treatment do you recommend?
  • Are there side effects of treatment?
  • How do I find my activity limits?
  • If I feel well enough, can I do more activities beyond my limits?
  • How can I improve my sleep hygiene?

A note from Cleveland Clinic

If you’re unable to get out of bed due to extreme fatigue, it can be difficult to get help for chronic fatigue syndrome. Don’t hesitate to call your healthcare provider to explain how your symptoms affect you. In some cases, a healthcare provider may schedule a virtual appointment with you so you can safely meet with a provider without leaving your home. An early diagnosis and treatment of this condition can help you feel better sooner.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 07/24/2023.

Learn more about our editorial process.

References

  • Arthritis Foundation (U.S.). Chronic Fatigue Syndrome. (https://www.arthritis.org/diseases/chronic-fatigue-syndrome) Accessed 7/24/2023.
  • Centers for Disease Control and Prevention (U.S.). Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. (https://www.cdc.gov/me-cfs/index.html) Last reviewed 5/18/2023. Accessed 7/24/2023.
  • Merck Manual. Chronic Fatigue Syndrome. (https://www.merckmanuals.com/professional/special-subjects/chronic-fatigue-syndrome/chronic-fatigue-syndrome) Last reviewed 9/2021. Accessed 7/24/2023.
  • National Library of Medicine (U.S.). Chronic Fatigue Syndrome. (https://medlineplus.gov/chronicfatiguesyndrome.html) Last reviewed 1/17/2023. Accessed 7/24/2023.
  • U.S. Department of Health and Human Services. Chronic Fatigue Syndrome. (https://www.womenshealth.gov/a-z-topics/chronic-fatigue-syndrome) Last reviewed 2/22/2021. Accessed 7/24/2023.

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