Chronic fatigue syndrome — also known as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) OR systemic exertional intolerance disease (SEID)— is a serious, chronic illness that can cause pain and extreme fatigue.

The Centers for Disease Control and Prevention (CDC) estimates that up to 3.3 million people in the United States have ME/CFS, most of whom do not have a diagnosis.

In the past, some people did not believe that ME/CFS was a real illness. However, experts have started to take it more seriously in recent years, and research is underway to find out why it happens and how to treat it.

Lifestyle strategies and medical treatment may help people manage some of the symptoms.

ME/CFS is a complex condition that can affect a range of bodily systems and functions.

Many of the possible symptoms resemble those of other conditions, making ME/CFS hard to diagnose.

The symptoms of ME/CFS can vary widely, but there are three core symptoms:

Reduced ability to function

A person with ME/CFS experiences fatigue that interferes with their ability to carry out daily tasks.

The fatigue:

  • is severe
  • does not improve with rest
  • is not due to activity
  • was not previously present

For a diagnosis of ME/CFS, this fatigue and the resulting decrease in activity levels must last 6 months or longer.

Post-exertional malaise

A person with post-exertional malaise (PEM) will experience a “crash” after physical or mental exertion.

During times of PEM, they may have new or worsening symptoms that include:

Following an event that triggers PEM, the person may be unable to leave the house, get out of bed, or do regular chores for several days or even weeks. The symptoms tend to become worse 12 to 48 hours after the exertion.

The trigger will depend on the individual. For some people, even having a shower or going to the grocery store can trigger PEM.

Sleep disorders

A range of sleep disorders can occur with ME/CFS. The person may feel very sleepy but be unable to sleep or not feel refreshed after sleeping. They may experience:

Other key symptoms

As well as the three core symptoms above, one of the following two symptoms must be present for a diagnosis of ME/CFS, according to the CDC.

  • Problems with thinking and memory: People may experience “brain fog“, which includes problems with:
    • making decisions
    • focusing on details
    • thinking quickly
    • remembering things
  • Dizziness when standing up: When the person moves from lying on their back to sitting or standing, they may experience:
    • dizziness
    • lightheadedness
    • faintness
    • vision changes, such as blurred vision or seeing spots

Other possible symptoms

Pain is a common symptom. A person with ME/CFS will often experience pain or discomfort that does not stem from an injury or other identifiable cause.

Common types of pain include:

  • muscle aches and pains
  • joint pain without redness or swelling
  • headaches

The person may also experience:

In addition, the American Myalgic Encephalomyelitis and Chronic Fatigue Syndrome Society (AMMES) notes that other possible symptoms include:

Experts do not know what causes ME/CFS, but some people with the condition say that it started after another health issue, such as:

  • a flu-like illness
  • a stomach bug or other infection
  • the Epstein-Barr virus, which causes mononucleosis, commonly known as “mono”
  • extreme physical stress, for example, surgery

There is growing evidence of a link between ME/CFS and the way the immune system works, but more research is necessary to establish the mechanism behind this.

According to the Office on Women’s Health, females are two to four times more likely than males to experience ME/CFS. The condition can also affect children, although this is less common.

The symptoms of ME/CFS vary widely and can resemble those of other conditions, which can make it difficult to diagnose.

If a person seeks medical help for ME/CFS, a doctor will likely begin the diagnostic process by:

  • asking about the person’s symptoms
  • carrying out a physical examination
  • recommending tests to try to identify the cause of any symptoms

To receive a diagnosis of ME/CFS, a person must have the three core symptoms of the condition for 6 months or longer. In addition, the doctor must be unable to find another explanation for the symptoms.

It can take time to eliminate other possible causes of ME/CFS symptoms, but there is no specific test that can identify the condition.

In 2018, researchers found that the levels of some molecules appeared to change when people had ME/CFS. One day, this may help make it easier to diagnose ME/CFS, but more studies are necessary before this can happen.

In 2019, another research team announced that they had made further progress in developing a test. The test focused on certain features of blood cells and electrical activity in people with ME/CFS.

In the past, many doctors did not believe that ME/CFS was a real disease, but major health organizations now recognize it.

Various advocacy groups, including Solve M.E., are working to promote awareness of ME/CFS and empower people with the condition to persist in getting a diagnosis.

The AMMES list other advocacy groups on their website, provide useful resources, and explain where people can get support.

There is currently no cure or treatment specific to ME/CFS, but a doctor may work with individuals to help them manage the symptoms. The treatment plan will vary among individuals, as ME/CFS affects people differently.

However, it may involve:

  • focusing on whichever symptom poses the greatest challenge
  • alleviating pain
  • learning new ways to manage activities

Managing PEM

One way to manage fatigue after activity is through pacing or activity management.

The person will work with a doctor to determine the best way to balance rest and activity. The doctor will also help them identify their personal triggers and establish how much exertion they can tolerate.

Sleep

ME/CFS causes fatigue and can also disrupt sleep. A doctor will encourage the person to establish healthy sleeping habits, such as a regular sleep schedule.

If these strategies do not help, the doctor may prescribe medication.

Pain

At first, a doctor may recommend over-the-counter (OTC) drugs for headaches and other types of pain. If these do not work, they may prescribe stronger medication.

A person with ME/CFS may be sensitive to various chemicals. Therefore, they should speak with a doctor before using any new medication.

Nondrug therapies that may help include:

  • gentle stretching and toning exercises
  • gentle massage
  • heat therapy
  • water therapy

Anxiety and depression

Anxiety and depression are common among people with ME/CFS. Antidepressant drugs may help some people, but they can sometimes make symptoms worse.

Lifestyle remedies that may help include:

Experimental medicines

Some laboratory research has investigated the potential action of rituximab (Rituxan), a cancer drug that targets certain cells in the immune system, for treating ME/CFS.

However, more research is necessary to ensure that the drug is safe to use in the treatment of this condition.

Various strategies can help people manage ME/CFS.

These include:

  • finding a doctor who understands the condition
  • seeking a counselor who can help manage the emotional and practical challenges
  • making family and friends aware of the symptoms and challenges
  • scheduling rest and activity times to maximize quality of life
  • using calendars and journals to help with memory lapses
  • learning which relaxation techniques are effective for them
  • following a balanced and nutritious diet
  • taking nutritional supplements if tests reveal a deficiency
  • finding someone to help with child care and household chores at difficult times, if possible

What about exercise?

Gentle stretching, yoga, and tai chi might be helpful in some cases, and at the right time, but vigorous exercise can make symptoms worse.

The CDC notes that exercise plans that benefit many people with chronic diseases are not usually suitable for people with ME/CFS, and they may be dangerous.

People with symptoms or a diagnosis of ME/CFS should not follow any type of activity plan without discussing it with their doctor first.

Can I live a normal life with CFS?

ME/CFS affects people differently and can impact lives in different ways. People with mild ME/CFS may be able to go to work or school and function well in other areas of life, although they may need to plan their activities carefully and schedule plenty of rest.

People with moderate ME/CFS may have difficulty performing daily tasks and attending work or school. Those with severe impairment may need to use a wheelchair or spend a lot of time in bed. They will likely need help with daily activities. People may have severe impairment for months or even years.

What foods should I avoid with chronic fatigue?

There is no research to suggest that limiting certain foods helps with CFS. However, if people have symptoms of irritable bowel at the same time, they can try to:

  • eat a variety of fresh fruits and vegetables
  • avoid sugary foods and refined grains, such as white bread and pasta
  • choose slow-release carbohydrates, such as brown rice, oats, and starchy vegetables
  • drink plenty of water or unsweetened beverages
  • avoid alcohol
  • cut out junk food

ME/CFS is a life changing condition that can affect every aspect of a person’s daily life.

It can take time to get a diagnosis, as the symptoms are not specific but overlap with those of other conditions. Whether or not a person has a diagnosis, lifestyle strategies can help them manage the challenges.

Until scientists find a specific treatment, coping strategies will play a key role in managing ME/CFS.