ME/CFS (Myalgic Encephalomyelitis/Chronic Fatigue Syndrome)

What is ME/CFS?

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), sometimes called ME, is a condition that affects multiple areas of the body. It causes long-lasting, extreme exhaustion that doesn’t get better with sleep. Other symptoms may include dizziness, pain, and problems thinking and sleeping. People with ME/CFS also have a symptom called post-exertional malaise (PEM). This means their symptoms get worse after thinking or moving. 

Many people with ME/CFS feel so sick that they can’t leave their beds or their homes, making it difficult to manage everyday life. But researchers are actively studying ME/CFS—providing hope for better ways to diagnose and treat the condition.

Symptoms of ME/CFS

People with ME/CFS can have a lot of different symptoms. These symptoms can also change over time, either getting better or getting worse. But all people with ME/CFS have the following symptoms:

• Extreme tiredness limiting physical activity that has lasted for more than six months
• Feeling much worse after moving or thinking, called post-exertional malaise (PEM)
• Waking up feeling tired even after getting enough sleep

People with ME/CFS also have one or both of the following symptoms:

• Problems thinking or concentrating
• Dizziness or fainting when standing or sitting up, called orthostatic intolerance (OI)

OI is common for people with ME/CFS. It happens when the body has trouble controlling blood pressure and heart rate when a person changes positions or stands still for too long. OI can cause dizziness, lightheadedness, or a heartbeat that is too fast.

Other symptoms of ME/CFS may include:

ME/CFS affects people differently, and symptoms can change over time. Some people feel better but still need to take things slowly to avoid feeling worse after moving or thinking because of PEM.

People may feel better for a while but then have a flare-up, and some symptoms can get worse. Compared to adults with ME/CFS, children and teens are usually more likely to recover partially or fully from the condition. 

Who is more likely to get ME/CFS?

Because ME/CFS is often undiagnosed, experts don’t know exactly how many people have it. Anyone can get ME/CFS, but it’s more common in women and teenagers. 

Different things can trigger ME/CFS, including a mix of one or more of the following:

• Infections: Most often, ME/CFS starts after an infection (from either a virus or bacteria). Many people develop ME/CFS after infection with the Epstein-Barr virus (the main cause of mononucleosis, or “mono”) or SARS-CoV-2 (the virus that causes COVID-19). 
• Immune system changes: In people with ME/CFS, their immune system doesn’t work right. White blood cells may be weaker, the body’s response to injury or illness (known as inflammation) may be overactive, and the immune system may mistakenly attack healthy cells.
• Sometimes people with ME/CFS have a major life event just before their ME/CFS symptoms start, like an accident, injury, surgery, childbirth, or strong physical or emotional strain. 
• Scientists who have studied how people with ME/CFS respond to physical activity have learned that their bodies have trouble turning oxygen and food into energy to move. 
• Genetics: ME/CFS can run in families. Variants (also called mutations) in a small group of specific genes may also cause ME/CFS. Variants in multiple genes may affect the body’s response to infection or chronic (long-term) pain.
• Non-genetic physical, social, and environmental factors that people in the same household share can also affect who gets ME/CFS.

How is ME/CFS diagnosed and treated?

Diagnosing ME/CFS

Because no single test can diagnose ME/CFS, doctors make a diagnosis by carefully reviewing symptoms, medical history, physical exam findings, and test results, and by ruling out other possible causes. They may also refer a person to specialists to check for other conditions with symptoms like those of ME/CFS. Those specialists could include neurologists, rheumatologists, cardiologists, endocrinologists, sleep specialists, or infectious disease doctors.

Learn more about neurological diagnostic tests and procedures.

Treating ME/CFS

Currently, there is no cure for ME/CFS. But many treatments can help relieve specific ME/CFS symptoms:

Post-exertional malaise (PEM)

A person with ME/CFS can pace themselves by carefully balancing activity and rest. Pacing can help avoid PEM flare-ups (sometimes called “crashes”). Keeping a diary of symptoms and when they happen can help people learn how to pace themselves. Some people with ME/CFS use wearable devices like smart watches or fitness monitors to track activity and heart rate, which may also help pacing and avoiding PEM.

Pain

Doctors may offer over the counter or prescription pain medicines to help people with ME/CFS who have headaches or pain in their muscles and joints. 

ME/CFS pain may also be reduced with gentle stretching to loosen muscles, simple strength exercises to keep muscles active, massage, heat, and warm water therapy to help a person relax and move more easily. Some people with ME/CFS get relief from acupuncture.

Mental health

Living with ME/CFS can be challenging, and people with the condition may also have depression, stress, or anxiety. These conditions can often be helped with medicines, counseling, deep breathing, muscle relaxation, massage, yoga, and tai chi. For people with ME/CFS who have trouble with memory, reminders and organizers can make daily tasks easier.

Orthostatic intolerance (OI)

People with ME/CFS who have OI may need to see a specialist, like a cardiologist or neurologist. These doctors can help rule out other health conditions that could cause similar symptoms like dizziness, lightheadedness, or feeling faint when standing.

If symptoms keep happening but the person doesn’t have a heart or blood vessel condition, a doctor may suggest drinking more fluids, increasing salt consumption, and using special socks or wraps that gently squeeze the legs.

Other strategies for managing symptoms

Rehabilitation specialists, physical therapists, or occupational therapists who are familiar with ME/CFS can help people adjust to daily living with the condition. For example, they may recommend finding ways to make activities easier, such as sitting while doing laundry or showering, taking frequent breaks during the day, and breaking up large tasks into smaller steps.

What are the latest updates on ME/CFS?

The National Institutes of Health (NIH), which includes NINDS, is the leading federal funder of research on the brain and nervous system, including disorders such as ME/CFS. NIH supports new and innovative research to better understand, diagnose, and treat ME/CFS.

Many scientists are trying to better understand ME/CFS so they can diagnose and treat the condition better. NIH has developed multiple working groups to address ME/CFS. The Trans-NIH ME/CFS Working Group, formed in 1999, brings together NIH staff to support and share research on ME/CFS.

The NANDS Council Working Group, formed in 2018, helps guide ME/CFS research. Based on a report by the group, the NIH began developing a plan to identify the best research strategies for people with ME/CFS in 2022. In 2024, the working group, along with many different researchers, doctors, advocates, and people with ME/CFS, created the ME/CFS Research Roadmap(pdf, 3436 KB) to guide future research. The report highlights eight important areas: the nervous system, immune system, metabolism, genetics, chronic infections, physiology, lesser-studied conditions, and circulation.