Health Topicschronic-painChronic fatigue syndrome

Chronic fatigue syndrome

Chronic fatigue syndrome (myalgic encephalomyelitis) causes overwhelming tiredness. Learn about the condition’s symptoms, treatments, and more.


Chronic fatigue syndrome (CFS) is a complex disorder that causes overwhelming tiredness, regardless of how well you sleep. It’s also known as myalgic encephalomyelitis (ME or ME/CFS) or systemic exertion intolerance disease (SEID). When you have CFS, even daily living can be exhausting. As many as 2.5 million people in the United States have CFS, although it’s estimated that up to 90 percent of cases are undiagnosed.

Discover more about CFS, including its possible causes and risk factors. Learn how this condition affects your body and what you can do to help ease symptoms and improve your well-being.

What is chronic fatigue syndrome?

tired woman with chronic fatigue syndrome lies back in bed

A full day of work, school, or parenting can leave anyone feeling exhausted. But chronic fatigue syndrome differs from everyday fatigue.

CFS refers to intense, debilitating fatigue that persists for at least six months and is unrelated to physical activity or sleep. CFS can last for several years or be a lifelong condition.

A person with CFS may have trouble:

  • Participating in activities they enjoyed before their illness 
  • Completing routine tasks like bathing or preparing meals
  • Getting out of bed or leaving their home
  • Attending work or school

At least one in four people with CFS is house- or bed-bound at some point during their illness, according to the Centers for Disease Control and Prevention (CDC).

Fatigue and other CFS symptoms tend to worsen after physical, emotional, or mental effort. This is referred to as post-exertional malaise (PEM).

CFS is a real condition, but there’s still much to learn about it. Many medical schools in the U.S. don’t include CFS in their physician training, leading to misdiagnoses and a lack of understanding about the condition and its treatment options.

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What are the signs and symptoms of chronic fatigue syndrome?

Chronic fatigue syndrome symptoms can vary from person to person. Symptoms may be mild or severe; they can be constant or they may come and go. Some people may feel like they have the flu at the onset of the condition.

The most common symptoms of CFS include:

  • Extreme fatigue that affects daily function
  • Joint or muscle pain (without redness or swelling)
  • Trouble thinking clearly, concentrating, or remembering things
  • Difficulty falling or staying asleep or feeling tired even after a full night of sleep
  • Dizziness, weakness, or lightheadedness, especially after standing up from a seated or lying position (a condition known as orthostatic intolerance)
  • Swollen, tender lymph nodes in the underarms or neck
  • Headaches
  • Sore throat

Less commonly, CFS symptoms may involve:

  • Night sweats and/or chills
  • Eye pain or changes in vision, such as blurriness or sensitivity to light
  • Low-grade fever
  • Mood swings, irritability, depression, or anxiety
  • Burning, numbness, or tingling sensations in the feet, hands, or face
  • New sensitivities to certain odors, medications, chemicals, or foods 
  • Gastrointestinal symptoms like constipation, diarrhea, bloating, or irritable bowel

CFS shares many symptoms with post-COVID-19 syndrome (also known as “long-haul COVID-19” or “long COVID”). This syndrome is characterized by COVID-19 symptoms that remain, return, or worsen four weeks after initially getting sick. Speak with a healthcare provider (HCP) about your symptoms. They can help you determine if your symptoms are related to CFS, post-COVID-19 syndrome, or another condition.

Post-exertional malaise  

Someone with chronic fatigue syndrome may experience post-exertional malaise (PEM) or “crashing.” PEM is a worsening of CFS symptoms that can occur after physical, emotional, or mental stress, such as running multiple errands or arguing with a loved one.

PEM may begin immediately after the event or several hours or days later. It can last for multiple days or weeks. Some people with PEM may have difficulty leaving their home or getting out of bed. 

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What causes chronic fatigue syndrome?

The causes of chronic fatigue syndrome aren’t fully understood. Some people with CFS say their symptoms started after experiencing a period of significant emotional or physical stress. Others developed CFS after becoming ill with a stomach virus, the flu, or a cold. CFS has also been reported following infection with the Epstein-Barr virus, which is responsible for an infectious disease called mononucleosis (or “mono”).  

Many medical experts believe multiple factors may play a role in the development of CFS, including:

  • Genetics: Some people with CFS have a family history of the syndrome and other conditions that cause fatigue. Research also shows links between CFS and certain genetic mutations (changes in genes that are sometimes inherited). 
  • Infections: Research suggests possible connections between CFS and various bacterial and viral infections, including those caused by the Epstein-Barr virus, parvovirus B19, and human herpesvirus 6 (HHV-6).  
  • Emotional or physical trauma: Profound emotional or physical trauma—such as experiencing a period of intense stress or sustaining a serious injury—may cause or contribute to CFS.
  • Immune system changes: Some research suggests that abnormal changes in the body’s immune system may lead to CFS. (The immune system is the network of organs, proteins, and cells that protects the body against infections and disease.)
  • Energy use problems: CFS is sometimes associated with abnormal changes to how the body produces and uses energy, particularly how the body converts sugars and fats into energy.

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What are the risk factors for chronic fatigue syndrome?

Anyone can develop chronic fatigue syndrome, including children, teens, and young adults. But certain risk factors can make you more likely to experience CFS.  

Established risk factors for CFS include:

  • Age: CFS is most common among people between 40 and 60 years old.  
  • Sex assigned at birth: People assigned female at birth are two to four times more likely to be diagnosed with CFS than people assigned male at birth.
  • Race: CFS occurs more frequently in white people than in individuals of other races. 
  • Personal medical history: People who have fibromyalgia or postural orthostatic tachycardia syndrome (POTS) may have an elevated risk of developing CFS. (POTS is a condition in which a person’s heart rate increases rapidly after standing up from a seated or lying position.)

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When should you see a healthcare provider?

Doctor speaks to a woman with chronic fatigue syndrome about a treatment plan

Feeling tired isn’t necessarily a reason to visit an HCP. Routine factors like stress, jet lag, poor sleep habits, and changes in diet and activity levels can cause occasional fatigue and leave you longing for a nap.

But it’s a good idea to consult with an HCP if you experience fatigue or exhaustion that is severe or persistent. This is especially true if fatigue is accompanied by other chronic fatigue syndrome symptoms like joint pain or headaches. Keeping a journal of your symptoms, including details of how certain factors influence them, can be helpful for both you and your HCP. 

Lingering fatigue is also a sign of many other medical conditions, from the common cold and dehydration to anemia, sleep apnea, type 2 diabetes, and cancer. Speak with an HCP if your fatigue:

  • Doesn’t have an obvious cause  
  • Persists for more than a few days
  • Begins abruptly 
  • Occurs with weight loss
  • Affects your ability to do everyday activities

It’s important to seek immediate medical care if you have fatigue that’s accompanied by:

Frequently feeling tired or drained can also be a sign of a mental health issue like depression or anxiety. If you’ve been feeling unusually sad, hopeless, frustrated, or anxious, consult with an HCP. They may refer you to a licensed mental health provider such as a counselor or psychologist.

To receive immediate assistance for severe emotional distress, contact the 988 Suicide and Crisis Lifeline by texting or calling 988. This service is free, confidential, and available 24/7.

What questions should you ask your healthcare provider?

Being candid with your HCP about your questions and concerns can help you learn more about your health and make educated decisions about your care. If you suspect you may have chronic fatigue syndrome, start by asking your HCP these basic questions:

  • What do you think is causing my fatigue? 
  • Are there any other possible causes of my fatigue aside from CFS?
  • What activities should I avoid? Do I need to limit physical activity?
  • What are my treatment options? Can you explain the benefits and risks of each? 
  • What lifestyle changes can help improve my symptoms? Should I explore alternative treatment options?
  • How can I improve my sleep habits? 
  • Should I speak with a mental health provider?

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How is chronic fatigue syndrome diagnosed?

There isn’t a standard diagnostic test for chronic fatigue syndrome. To learn more about your health and to make a diagnosis, your HCP will likely start by asking you questions about your symptoms and personal and family medical history.

They may ask you if certain activities make you feel better or worse (for example, whether exercise raises or lowers your energy levels). They may also ask how your symptoms affect your ability to complete everyday tasks. You might also be asked about your mental health and if you’ve been feeling unusually sad or anxious lately.

Your HCP may then perform a physical exam to check for signs of illness, such as swollen lymph nodes. Urine and blood tests can also help rule out other possible medical causes of your symptoms.

You may receive a diagnosis of CFS if all of the following criteria are present:

  • You display the main symptoms of CFS, including severe fatigue and exhaustion that doesn’t improve with rest, worsens after physical or mental effort, and interferes with your ability to function. 
  • Your symptoms persist or have persisted for six months or longer and are of severe or moderate intensity at least half of the time. (The timespan for a diagnosis in children is three months of symptoms.)
  • There is no clear explanation for your symptoms.

Based on your symptoms and other conditions you may have, your HCP might refer you to a specialist for more advanced care. This could include a sleep specialist, a rheumatologist (a medical doctor who treats inflammatory and autoimmune conditions that affect the skeleton, such as rheumatoid arthritis), or a neurologist (a medical doctor who treats conditions of the brain, nerves, and spinal cord).

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How is chronic fatigue syndrome treated?

Mature couple meditate together in a park to treat chronic fatigue syndrome

Chronic fatigue syndrome is a long-term illness that doesn’t yet have a cure. Treatment for CFS generally focuses on:

  • Increasing energy levels and reducing symptoms like joint pain
  • Improving daily function
  • Avoiding post-exertional malaise

CFS is a complex disease that can cause a range of mild to severe symptoms. As such, CFS treatment plans vary from person to person. Your best course of care will depend on your symptoms, how they affect your daily routine, and your treatment goals and preferences. You and your HCP will likely first attempt to address symptoms that you find to be the most disruptive to your life.  

Many CFS treatment plans involve a combination of several approaches, including:

Lifestyle changes for chronic fatigue syndrome

There’s no magic diet, supplement, or morning routine that can reverse chronic fatigue syndrome. But making some relatively small lifestyle changes can help some people improve their symptoms and function better. With your HCP’s guidance, you might try the following:

Implement healthy sleep habits. This can include:

  • Following a set sleep schedule
  • Avoiding large meals, caffeine, or alcoholic beverages late at night
  • Putting away your smartphone before getting into bed

It’s also a good idea to avoid napping during the day. If you do nap, limit naps to no more than 30 minutes at a time.

Explore pain management techniques. Gentle massages, heat therapy, stretching, acupuncture, and water therapy (such as float therapy or gentle swimming) can be helpful for some people with muscle or joint pain from CFS. Ask your HCP about pain management techniques that would be appropriate for you. They may refer you to a pain management specialist for additional care. 

Prioritize your mental health. Time-tested relaxation techniques such as deep breathing, meditation, gentle yoga, tai chi, and journaling can help you cope with the mental health effects of a CFS diagnosis. You may also want to consider speaking with a mental health provider.

Get organized. CFS can make you feel scattered or forgetful. Stay on track by using a daily planner or by writing important tasks and dates in a calendar. Keeping a small notebook on hand or using your smartphone to set reminders, create to-do lists, or jot down people’s names may also be helpful.

Medication for chronic fatigue syndrome

Medication may be used to improve certain CFS symptoms, including:

  • Pain: Taking an over-the-counter (OTC) pain medication such as naproxen sodium or ibuprofen may help relieve muscle or joint pain caused by CFS. If OTC options are ineffective, your HCP may prescribe other medications that can be used to relieve muscle or nerve pain. This might include gabapentin, pregabalin, duloxetine, or amitriptyline. 
  • Sleep problems: If working to improve your sleep habits or taking an OTC sleep aid isn’t enough to enhance your sleep quality, your HCP may prescribe a low-dose sleep aid for short-term use.
  • Orthostatic intolerance: Your HCP may recommend medication to help regulate your heart rate or blood pressure if standing from a seated or lying position makes you feel dizzy, weak, or makes you faint.
  • Depression or anxiety: Living with a chronic condition such as CFS can contribute to common mental health concerns like depression and anxiety. Taking antidepressant or anti-anxiety medication may be helpful if non-drug approaches (such as stress-reduction techniques or speaking with a mental health provider) aren’t enough to improve your symptoms.  

Post-exertional malaise prevention

Much of chronic fatigue syndrome treatment focuses on avoiding the effects of post-exertional malaise (PEM), which can occur after physical, mental, or emotional activity. PEM can trigger days or weeks of worsening CFS symptoms. There are several ways in which your HCP may help you reduce the effects of PEM:

Understand your limits

The first step in avoiding PEM is identifying your threshold for exertion. How much activity someone can handle without experiencing PEM is sometimes called an “energy envelope.” Staying within your energy envelope and finding a balance of activity and rest are essential parts of managing CFS. Being mindful of your activity levels to avoid worsening CFS symptoms is also called “pacing.”

It’s important to remember that no two cases of CFS are the same. Your physical and emotional limits may look different from those of someone else and your limits may change over time. Writing down how everyday activities and events influence your symptoms in a journal can help you identify your limits and determine what lies within your energy envelope.

Pace yourself

CFS is an illness of easier days and more difficult days. On challenging days, simple tasks like washing your hair or speaking with a co-worker may be strenuous enough to trigger PEM. These situations are sometimes unavoidable, but mindful pacing can help you avoid “pushing” and “crashing.”

For instance, on days when you feel stronger, you may be tempted to push yourself physically or mentally beyond your energy envelope. In many cases, however, this may result in a PEM crash that can turn what seemed like a productive day into a difficult one.

Be cautious with exercise

Exercise is beneficial for many people with chronic illnesses, but this generally isn’t the case for people with CFS. Many types of exercise—particularly vigorous aerobic exercises like jogging and playing basketball—aren’t recommended for most people with CFS.

Low-impact activities like gentle yoga or walking, swimming, or cycling at a slow pace may be tolerated by people with milder types of CFS. Still, it’s important to listen to your body and check with your HCP before trying new exercises. Some HCPs may recommend graded exercise therapy (GET), which involves a gradual, supervised increase in physical activity over several months.

With this in mind, learning to function to the best of your ability with CFS (while staying within your energy envelope) is necessary to managing the condition. Do what you can, but take breaks as needed and try not to push yourself too hard.

Seek help when you need it

Learning how to avoid PEM and manage CFS symptoms can involve some trial and error. If you’re unsure of your capabilities or how to prevent PEM, your HCP can help determine what activities may be hurting or helping you. They may also refer you to a specialist (such as a rehabilitation professional) who can suggest ways to conserve your energy and make completing everyday tasks easier. This might include using a wheelchair on challenging days, taking seated showers, or dividing chores or necessary activities into small chunks.

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What are the possible complications of chronic fatigue syndrome?

Chronic fatigue syndrome can lead to mental health complications like depression or anxiety. For example, exhaustion caused by CFS may make you feel unmotivated, hopeless, or deeply sad. You may be anxious about pushing yourself too hard and inadvertently causing post-exertional malaise. Disruptions in your ability to work, attend school, parent, or go to social events can also cause frustration or loneliness.

Speaking with a mental health provider is helpful for many people with CFS. Treatments like cognitive behavioral therapy (a common form of talk therapy) can help you cope with the mental health effects of chronic fatigue syndrome and boost your mood. In fact, some research suggests that receiving cognitive behavioral therapy may improve fatigue and physical functioning in people with CFS.  

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Can you prevent chronic fatigue syndrome?

There’s no known way to prevent chronic fatigue syndrome. Researchers are currently learning more about the possible causes of CFS and ways the condition may be prevented.

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What is the outlook for chronic fatigue syndrome?

There’s currently no cure for chronic fatigue syndrome. Treatment can help relieve CFS symptoms and improve quality of life in many cases. It’s also possible to return to pre-illness functioning, though most people deal with at least mild fatigue in the long term.  

Learning about CFS can help give you an idea of what to expect. Just remember that your condition is real and unique to you. CFS affects everyone differently. To learn more about your individual CFS prognosis and how you can keep your symptoms in check, speak with your HCP.

Working with chronic fatigue syndrome

Chronic fatigue syndrome may affect your ability to work a full day or fulfill your job obligations. In fact, only about half of people with CFS hold full-time or part-time jobs. If CFS is disrupting your ability to work, consider speaking with your employer about possible workplace accommodations for your condition. This might include adjusting your schedule, using a wheelchair, or taking periodic rest breaks.    

The Americans with Disabilities Act (ADA) offers protections for people with substantial disabilities from chronic conditions like CFS. The act requires that employers make efforts to provide arrangements that allow people with disabilities to perform their jobs. For a person with CFS to be protected under the ADA, they must experience a mental or physical impairment that significantly limits one or more major life activities.

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Living with chronic fatigue syndrome

Woman with chronic fatigue syndrome taking supplements to ease symptoms and promote good health

Chronic fatigue syndrome is a real illness that’s poorly understood by many professionals in the medical community. It’s important to find an HCP who takes your condition seriously and who acknowledges that your symptoms are not just ordinary fatigue or a figment of your imagination. With support from your HCP and a little patience as you learn your limits, you can manage CFS.

If you’re living with CFS, you can prioritize your health and help improve your well-being with simple, everyday measures like these:

Eat a nutritious, balanced diet. Nourishing your body by eating plenty of vegetables, fruits, whole grains, lean proteins, and moderate amounts of healthy monounsaturated and polyunsaturated fats is important if you have a chronic illness like CFS. 

Consider taking nutritional supplements. Your HCP may perform tests to see if you’re deficient in important nutrients like magnesium, zinc, or vitamin C. If you are, they may recommend taking one or more nutritional supplements. Be sure to check with your HCP before trying a new supplement, as some can negatively interact with certain medications or other supplements you may be taking.

Find enjoyable, energy-sparing activities. You can still have fun while living with CFS. Creating art, solving puzzles, cooking your favorite comfort food, and reading a good book in the sun are just a few examples of low-impact activities that you may be able to enjoy by yourself or with loved ones. 

Use energy-conserving tools. Using a wheelchair or motorized scooter when navigating the grocery store can help you save your energy, as can sitting on a bath seat while taking a shower.

Share your feelings. Many people with CFS find it helpful to share their thoughts, concerns, and frustrations with loved ones or mental health providers. Joining an in-person or online support group for people with CFS can also help you connect with others who face similar challenges.

To discover more about chronic fatigue syndrome, its symptoms, and how you can cope, reach out to your HCP. You can also find patient stories, caregiver resources, and other helpful information on the Centers for Disease Control and Prevention website.  

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Featured CFS articles

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Adamson J, Ali S, Santhouse A, Wessely S, Chalder T. Cognitive behavioural therapy for chronic fatigue and chronic fatigue syndrome: Outcomes from a specialist clinic in the UK. J R Soc Med. 2020;113(10):394-402.   

BetterHealth Channel. Department of Health, State Government of Victoria, Australia. Chronic Fatigue Syndrome (CFS). Accessed January 9, 2024.

Centers for Disease Control and Prevention. Diagnosis of ME/CFS. Last reviewed January 27, 2021.  

Centers for Disease Control and Prevention. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome – Information for Healthcare Providers. Additional Strategies for Living with ME/CFS. Last reviewed April 30, 2021.

Centers for Disease Control and Prevention. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome – Information for Healthcare Providers. Treating the Most Disruptive Symptoms First and Preventing Worsening of Symptoms. Last reviewed April 30, 2021.  

Centers for Disease Control and Prevention. Tips for Better Sleep. Last reviewed September 13, 2022.

Centers for Disease Control and Prevention. Treatment of ME/CFS. Last reviewed January 28, 2021.

Centers for Disease Control and Prevention. What is ME/CFS? Last reviewed March 21, 2023.

Cleveland Clinic. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Last reviewed July 24, 2023.  

Job Accommodation Network. About Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Accessed January 3, 2024.

Larun L, Brurberg KG, Odgaard-Jensen J, Price JR. Exercise therapy for chronic fatigue syndrome. Cochrane Database Syst Rev. 2017;4(4):CD003200. Published 2017 Apr 25.

Mayo Clinic. COVID-19: Long-Term Effects. Last reviewed June 22, 2023.

Mayo Clinic. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Last reviewed May 11, 2023.

Office on Women’s Health. Chronic Fatigue Syndrome. Last updated February 22, 2021.

Sapra A, Bhandari P. Chronic Fatigue Syndrome. StatPearls. Last updated June 21, 2023.

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