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Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

British Columbia Specific Information

Many Canadians are affected by complex chronic diseases (CCD). CCD’s are illnesses that last a long time, require treatment and management, and often do not get better on their own. Fibromyalgia (FM), Myalgic Encephalomyelitis (ME), which is also called Chronic Fatigue Syndrome (CFS), and Chronic Lyme Disease  are examples of complex chronic diseases.

To learn more about fibromyalgia, myalgic encephalomyelitis or chronic Lyme-like disease, visit HealthLinkBC’s  Complex Chronic Diseases health feature.

Topic Overview

What is myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)?

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) (say "my-AL-jik en-seh-fuh-loh-my-uh-LY-tus") is a condition that makes you feel so tired that you can't do all of your normal, daily activities. There are other symptoms too, but being very tired is the main one. Some people have severe fatigue and other symptoms for many years. 

What causes ME/CFS?

Doctors don't know what causes ME/CFS. It seems to follow after a flu-like illness like Epstein-Barr Virus (EBV). High stress may also lead to ME/CFS for some people. And changes in a person's immune system may also play a role. It's likely that a number of factors or triggers come together to cause ME/CFS.

What are the symptoms?

Symptoms can vary with ME/CFS. If you have ME/CFS:

  • You feel exhausted all or much of the time. And it doesn't get better with rest.
  • Your symptoms may flare up after a mental or physical activity that used to be no problem for you. Often there is a delay before it starts. And it can take days, weeks, or more to feel better.
  • You have problems sleeping. Or you may wake up feeling tired or not rested.
  • It may be harder for you to think clearly, to concentrate, and to remember things.
  • You may feel dizzy, weak, or in more pain when you have been standing or sitting upright for a long time.
  • You may also have headaches, muscle and joint pain, a sore throat, and tender glands in your neck or armpits.

Depression is common with ME/CFS, and it can make your other symptoms worse.

How is ME/CFS diagnosed?

To be diagnosed with ME/CFS, you must have all of these symptoms:footnote 1

  • Major decrease in your ability to do the things you did before you got sick—including work, school, social, or personal activities—that has continued for more than 6 months.
  • Worsening of symptoms after being mentally or physically active (post-exertional malaise).
  • Sleep problems, including not feeling rested after sleeping (unrefreshed sleep).
  • Extreme fatigue that is:
    • New or has not been a lifelong problem.
    • Not caused by being active for a long period of time.
    • Not much better after resting.

You must also have one or more of these symptoms:

  • Problems with concentration, short-term memory, or thinking of the right word (cognitive impairment).
  • Feeling dizzy or faint while standing or sitting upright that improves while lying down (orthostatic intolerance).

Doctors may also look for other causes of your symptoms. They may also do additional tests to confirm your diagnosis.

How is it treated?

There is no treatment for ME/CFS itself, but many of its symptoms can be treated. A good relationship with your doctor is important. That's because the two of you will need to work together to find a combination of medicines and lifestyle adjustments that will help you get better. Some trial and error may be needed, because no single combination of treatments works for everyone.

Home treatment is very important. You may need to change your daily schedule, learn better sleep habits, and use regular gentle movement or exercise to manage fatigue. Even at times when you have more energy, keep a low-key pace throughout each day. Rest often.

When you have ME/CFS, you may not be able to do the things you would like to do. This may lead to feelings of frustration and anxiety. It can also lead to depression. Depression is not the same thing as ME/CFS. But it can make your ME/CFS symptoms worse.

Learning to cope with your symptoms and talking to others who have ME/CFS can help. So can working with a counsellor.

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Doctors don't know what causes ME/CFS. It seems to follow after a flu-like illness like Epstein-Barr Virus (EBV). But EBV doesn't cause all cases of ME/CFS. Other infections like parvovirus B19 and Ross River virus may also be linked to ME/CFS.

High stress may also lead to ME/CFS in some people. This could be a period of high physical or emotional stress or a major life event.

Changes in a person's immune system may also play a role.

It's likely that a number of factors come together to cause ME/CFS.


ME/CFS symptoms usually start suddenly. But for some people, they develop gradually over weeks or months. Symptoms can change in a day, and from day to day. And how severe the symptoms are can differ from person to person.

Symptoms can vary with ME/CFS. But there is a core set of symptoms that affect nearly everyone with ME/CFS. These core symptoms are:

  • Extreme physical fatigue, mental fatigue, or both. It can be constant, or it can come and go. It is not relieved by rest. This fatigue also is so severe that it interferes with your work, your play, and your social activities.
  • Worsening of symptoms after activity. This is called post-exertional malaise. This can mean you feel ill or weak or your ME/CFS symptoms are worse after physical or mental activity. Even daily activities like showering, cooking, and reading can trigger symptoms. Often there is a delay of 24 hours before it starts. It can take days, weeks, or more to feel better.
  • Trouble sleeping. Or you may wake up feeling tired or not rested.
  • Problems with concentration, short-term memory, or thinking of the right word (cognitive impairment).
  • Feeling dizzy, faint, or in more pain while standing or sitting upright for a long time (orthostatic intolerance). These symptoms get better or go away when you lie down.

ME/CFS may also cause the following symptoms. These may be just as common as the core symptoms. Different people with ME/CFS have different combinations of:

  • Pain, which can be widespread or in one place. ME/CFS pain can be in one area, then move to another. You may have:
    • Muscle pain.
    • Joint pain.
    • Headache.
  • Tender glands in your neck or armpits.
  • Sensitivity to light, noise, chemicals, and certain foods.
  • Flu-like symptoms like fever and sore throat.
  • Urinating often.
  • Digestive issues like bloating, abdominal pain, nausea, diarrhea, or constipation.
  • Low body temperature, cold hands and feet, sweating, or trouble with heat or cold.
  • Feeling worse after any kind of physical or emotional stress.
  • Weight change or appetite change.

It's common for people with a chronic condition like ME/CFS to feel depressed. Some may grieve the loss of the active life they once had. If you feel depressed, talk with your doctor. Treatment for depression may prevent ME/CFS symptoms from getting worse.

What Happens

ME/CFS may come upon you gradually or quite suddenly. Because the symptoms can be vague and can be caused by many things, you might not pay attention to the problem for several weeks or months. It is hard to say what is normal with ME/CFS. That's because the diagnosis often is not clear for some time.

In general, most people with ME/CFS:

  • Feel that the illness doesn't improve over time.
  • Report that symptoms are always present. But from day to day, symptoms may be better or worse.

But some people with ME/CFS may:

  • Feel that the illness gets worse over time.
  • Notice that their symptoms go away completely for a period of time and then return.
  • Notice that their symptoms get better with treatment for a period of time, but they don't return to feeling as well as they did before the illness.

Most people with ME/CFS find that their symptoms greatly reduce their ability to do the things they want and need to do. But ME/CFS is different for everyone.

Most people are not able to work or go to school full-time. Some people are able to do some of their usual activities at work or school. They often have to cut down on social and recreational activities to save their energy. But ME/CFS affects other people more severely. They may have trouble getting out of bed or need help with basic activities such as dressing, eating, and bathing.

On days when they feel better, many people who have ME/CFS will try to "push" themselves to do as much as they can. But this often causes their symptoms to get worse the next day. Many call this a "crash." (It's also called post-exertional malaise.) But over time, this "push-crash" cycle can lead to worsening symptoms and more days recovering from doing too much.

What Increases Your Risk

ME/CFS can occur at any age. But it seems to be most common in people who are 25 to 45 years of age. It can happen to both men and women, but it seems to be more common in women.

ME/CFS is rare in children. It may occur in teens, especially after having mononucleosis.

When should you call your doctor?

It's important to talk to your doctor about any symptoms you may have.

Call your doctor if you have:

  • Severe fatigue that lasts longer than 2 weeks, causes you to limit your usual activities, and does not improve with rest.
  • Sleep problems that last for more than 1 to 2 months. These problems may include being unable to fall asleep or stay asleep, tossing and turning, and waking up feeling tired or not rested.
  • Swelling in the glands in your neck or armpits (without other signs of infection) that lasts for at least 2 weeks.
  • Severe fatigue along with frequent urination (especially at night), extreme thirst, weight loss, or blurred vision. Fatigue that occurs with some or all of these may be a symptom of undiagnosed diabetes.
  • Severe headache that does not improve with home treatments.

Watchful waiting

Watchful waiting is a wait-and-see approach. A month or two of paying close attention to your sleep habits, trying to control stress, and eating a balanced diet will take care of most cases of fatigue not caused by ME/CFS or another medical problem. But if your fatigue has not improved after 1 to 2 months of self-care, or if fatigue won't go away and limits your usual activities, call your doctor.

If you have been diagnosed with ME/CFS, pay attention to any new symptoms and report them to your doctor. Although ME/CFS can cause a variety of symptoms, new symptoms could be caused by another illness or medical condition that may need to be evaluated and treated.

Examinations and Tests

Doctors use a specific list of symptoms to diagnose ME/CFS. Sometimes they may have you track your symptoms, activity, and rest in a diary. Since symptoms of ME/CFS can be similar to other conditions, doctors may do additional tests to confirm a diagnosis of ME/CFS. Or they may use a variety of tests to rule out other conditions.

Tests that may be done to confirm a diagnosis of ME/CFS may include:

  • Orthostatic testing. Two types of tests may be done to see if you have symptoms after being upright for long periods of time. The tests may include a 10-minute standing or leaning test after lying down and a 30- to 45-minute upright tilt table test. The doctor will have you stand or sit upright for a period of time. He or she will ask you to report any symptoms or change in symptoms as they happen.
  • Neuropsychological testing. This may be done to see if you are having problems with your ability to think, concentrate, or remember.
  • Cardiopulmonary exercise test (CPET). This may be done to see if you recover after physical activity. Often the test is done and repeated about 24 hours later.

Tests to rule out other conditions usually include:

  • Complete blood count (CBC). This gives important information about the kinds and numbers of cells in your blood.
  • Erythrocyte sedimentation rate (ESR). This test measures how quickly red blood cells (erythrocytes) settle in a test tube. This tells whether or not certain types of inflammation are present.
  • Thyroid-stimulating hormone test. It's used to find problems that affect the thyroid gland.
  • Chemistry panel. This is a blood test that provides information about your general state of health.
  • Urinalysis, a urine test that can provide information about your overall health and clues to many conditions.

Based on your symptoms, the doctor may do additional tests to look for signs of a chronic infection, autoimmune disease, or low levels of hormones.

If there is a concern about your immune system, your doctor may refer you to another specialist like an immunologist.

Treatment Overview

Since there is not yet a cure for ME/CFS, the keys to living with ME/CFS are learning how to pace your activities and treating your symptoms.

  • Find a primary doctor who understands ME/CFS, knows how to treat it, and who helps you feel supported.
  • Track what helps you feel better, as well as the things that make your symptoms worse.
  • Use a mix of medical care, daily self-care, and support.
  • For regular support you can count on, work with a professional counsellor, a ME/CFS support group, or both.
  • Get specialist care when you need it. Sign "release of information" forms so that your doctors can work together as a team.

Treat the worst first

Start by listing your worst symptoms—the ones that make it hardest to get through the day. With your doctor, focus first on treating those symptoms. Decide whether a specialist might be helpful for any of them.

The most common ME/CFS symptoms can also be the most treatable.

Symptoms worse after activity (post-exertional malaise)

Learning how to manage your activity can help you be as active as possible without causing your symptoms to get worse. This includes:

  • Estimating how much energy you have on a given day. This is sometimes called your "energy envelope." You spend only that much energy, and not more.
  • Estimating how much energy an activity takes and how long you can do that activity. You stop when you reach that time, and then take a break.
  • Not pushing yourself to get more done on days you feel well.
  • Adapting activities to make them easier. One example is sitting down while doing the dishes.


Good sleep habits can help improve the quality of your sleep. If you also try medicine for sleep, it's best to start on a low dose. Certain antidepressants help with sleep, mood, and chronic pain, so your doctor may suggest trying one.

Feeling dizzy or weak while sitting or standing (orthostatic intolerance)

Your doctor may have you wear pressure stockings, put your legs up while sitting, or increase your salt intake. Your doctor may also suggest medicines like fludrocortisone or midodrine.


Different kinds of pain can be treated in different ways. If one treatment doesn't work, you and your doctor can try another until you find what works best for you.

  • It's important to control focused pain, such as arthritis or migraine. This kind of pain can make ME/CFS body pain worse. First try an over-the-counter pain reliever, like acetaminophen (such as Tylenol), ibuprofen (such as Advil or Motrin), or naproxen (such as Aleve). Be safe with medicines. Read and follow all instructions on the label.
  • There are different types of prescription medicines that help with pain, such as antidepressants or anticonvulsants for chronic pain.
  • Other treatments that can help with ME/CFS pain include acupuncture or massage. Yoga may also help. Look for a gentle form of yoga. It may be best to start off with short sessions at home.

Depression, anxiety, and distress

When you have ME/CFS, you may not be able to do the things you would like to do. This may lead to feelings of frustration and anxiety. It can also lead to depression. Depression is not the same thing as ME/CFS. But it can make your ME/CFS symptoms worse.

  • Work with your doctor to watch for signs of depression. People with depression often feel better after exercise, but people who have ME/CFS often feel worse.
  • If your doctor suggests an antidepressant, ask if there is one that can help control your pain and help you sleep, as well as improve your mood.
  • For support and help with mood problems, you can also work with a professional counsellor who understands ME/CFS.

Get specialist care when you need it

Visit your doctor every few months to help track your symptoms and check for any need to change your treatment.

Get specialized care if you need it. For example:

  • A rehabilitation specialist can help you treat pain and improve your ability to do your daily tasks.
  • A pain management specialist can offer a number of pain treatments.
  • There are some specialists who work with experimental treatments such as antiviral medicines.

What to think about

Along with the treatment you get from your doctor, you might find that other treatments help too. Some people may try different diets or natural health products to help manage their symptoms. If you try a new diet or natural health product pay attention to how your body and symptoms respond to it. It may help to work closely with your doctor to figure out what works best for you.

Your mind and body are connected and affect each other. Physical illnesses can be made worse—or better—by your feelings and attitudes, and vice versa. Learn as much as you can about ME/CFS. Then work with your doctor to learn ways to cope with your symptoms. Get emotional support from your health professionals as well as from your family and friends.


Experts don't know if ME/CFS can be prevented or cured. But treatment can help people manage ME/CFS symptoms.

Home Treatment

Home treatment is the most important part of treating ME/CFS. You can take steps to control and sometimes relieve your ME/CFS symptoms:

    • Adjust your schedule to take advantage of times when you have more energy and feel less tired. Keep a diary for a week or so. Write down the times of day when you have energy and when you are tired. If there is a pattern to how your energy level changes during the day, try to plan your work, school, or other activities around that pattern.
    • Do what you can to take charge of your fatigue level. Try not to do too much when you have more energy. If you do too much, you may become overtired. And it may take several days for you to recover.
    • Improve your sleep habits. Sleep problems may add to your fatigue and other symptoms.
      • Go to bed only when you are sleepy. Get up at the same time every day, whether or not you feel rested.
      • If you lie awake for longer than 15 minutes, get up, leave the bedroom, and do something quiet until you feel sleepy again.
      • Avoid alcohol, caffeine, and tobacco well before bed. Alcohol can disrupt your sleep when you drink it within 4 hours of bedtime. Caffeine is a stimulant that stays in the body for 12 hours. So make sure to avoid it during that block of hours before your bedtime.
      • Keep the bedroom at a comfortable temperature. Get rid of all sound and light disturbances.
      • Make sure your mattress provides good support. Use a neck support pillow to keep your head and neck from moving too much when you sleep.
      • Take naps if you need to. Keep them short (20 to 60 minutes). And try not to take them late in the day or evening.
    • Try getting light, gentle exercise regularly. Stretching is a good start. Light aerobic exercise such as walking, swimming, or riding a bicycle or stationary bike can also be helpful. Try to keep a balance between being active enough to benefit from it and exercising so much that you become overtired.  
    • Try taking non-prescription pain medicines to relieve muscle and joint pain and headaches caused by ME/CFS. Medicines that may be helpful include acetaminophen (such as Tylenol), ibuprofen (such as Advil or Motrin), and naproxen (such as Aleve). Be safe with medicines. Read and follow all instructions on the label. Talk to your doctor if your pain is not relieved by non-prescription medicine.
    • Join a support group. These groups can be a good source of information and tips for managing your illness. They also give you a chance to share your frustrations and problems with others who have ME/CFS. Ask your doctor or contact a local hospital for the location of a support group near you.
    • Eat a balanced diet. Include plenty of fruits, vegetables, grains, cereals, legumes, poultry, fish, lean meats, and low-fat dairy products.

Try to be patient. Keep in mind that daily home treatment usually helps relieve or control ME/CFS symptoms.


Medicines do not cure ME/CFS. But they can help relieve your symptoms.

Medicine choices

Over-the-counter medicines include:

  • Pain relievers and anti-inflammatory drugs:
    Over-the-counter drugs include acetaminophen (for example, Tylenol), ibuprofen (for example, Advil, Motrin), and naproxen (for example, Aleve). They sometimes relieve frequent or severe joint and muscle pain, headaches, and fevers. Be safe with medicines. Read and follow all instructions on the label. Talk to your doctor if your pain is not relieved by non-prescription medicine.

Prescription medicines include:

  • Anticonvulsants, also called antiseizure medicines. This type of drug, such as gabapentin and pregabalin, is sometimes prescribed for pain and sleep problems. It seems to work best when used for nerve pain.
  • Antidepressants. Antidepressant medicine is prescribed by a doctor to ease depression, anxiety, and pain. They may also help improve your ability to concentrate and help you sleep better.
  • Other medicines, such as fludrocortisone or midodrine. These may help you feel less dizzy or weak when sitting up or standing after lying down.

For more information about treating some types of pain that may occur with ME/CFS, see:

What to think about

Depression often becomes a part of ME/CFS and can make your symptoms worse. Like any medical illness, depression needs to be treated. If you have ME/CFS and feel depressed, talk to your doctor and get treatment.

Other Treatment

The best treatment for your ME/CFS is what makes you feel better. Along with daily self-care and the treatment you get from your doctor, you might find that other treatments help too.

There are safe non-traditional treatments that can relieve pain and stress, ease muscle tension, help you feel better and healthier, and improve your outlook and quality of life.

Treatment choices

Some popular complementary treatments include:

Some types of yoga may be very intense and cause your symptoms to worsen. Look for a gentle form of yoga. It may be best to start off with short sessions at home so that you can take breaks. Over time, you can slowly work up to longer yoga sessions.

Some people may try different diets or natural health products to help manage their symptoms. This is because they may notice new sensitivities to certain foods and chemicals. If you try a new diet or natural health product, pay attention to how your body and symptoms respond to it. It may help to work closely with your doctor to figure out what works best for you and your symptoms.

What to think about

None of these complementary treatments have been proven effective in treating ME/CFS, but some people have reported feeling better after using them. If you have ME/CFS and are thinking about trying a complementary treatment, get the facts before you begin. Consider these questions with your doctor:

  • Is it safe? Do not use treatments that could harm you, such as unusual diets or excessive vitamin or mineral supplements. (A daily multiple vitamin is okay. Try to avoid taking more than 100% of the recommended dietary allowance for any vitamin or mineral unless your doctor prescribes it.)
  • Is the product manufactured reliably? Natural health products are not subject to the same regulations as medicines. Ingredients may vary from one maker to another. Read the labels carefully, and choose well-known brands you trust.
  • Does it work? It may be hard to tell whether a treatment is working. Keep in mind that when you get better after treatment, the treatment may not be the reason for your improvement. Symptoms of ME/CFS often improve on their own. Or the treatment may be causing a placebo effect, which makes you feel better.
  • How much does it cost? An expensive treatment that may or may not help you may not be worth the high cost. Beware of products or treatment providers who require a large financial investment up front or a series of costly treatments.
  • Will it improve my general health? Even if complementary treatments are not effective in treating ME/CFS, some of them are safe and healthy habits that may improve your general well-being and may be worth trying.

Avoid products that claim to have a "secret" ingredient or that claim to cure ME/CFS. Currently, there is no cure for ME/CFS. Any benefit reported as a result of using a product is most likely due to improved symptom management, chance, or, possibly, the illness running its course.

For more information, see the topic Complementary Medicine.



  1. Institute of Medicine (2015). Beyond myalgic encephalomyelitis/chronic fatigue syndrome: Redefining an illness. Institute of Medicine. Accessed January 31, 2017.

Other Works Consulted


Adaptation Date: 4/28/2022

Adapted By: HealthLink BC

Adaptation Reviewed By: HealthLink BC