What is chronic fatigue syndrome?

Chronic fatigue syndrome (CFS) is a condition marked by profound tiredness, regardless of sleep. It's also called myalgic encephalomyelitis (ME). Symptoms often get worse with minimal physical or mental activity. CFS can happen suddenly and last for years. Females are more affected than males.

What causes chronic fatigue syndrome?

The cause of CFS isn't known. It may be from a viral infection in some people. But the exact cause is almost always unclear. Other possible causes being studied are genetics and immune system problems.

Who is at risk for chronic fatigue syndrome?

Because the cause of CFS isn't known, it’s hard to know what might put someone at risk for getting the condition. But certain factors are seen more often in people with CFS. These include:

• Being female. CFS happens up to 2 to 4 times more often in women than in men.

• Age. CFS often affects middle-aged people. But people of any age can get it.

What are the symptoms of chronic fatigue syndrome?

Symptoms of CFS are often nonspecific and can be seen with viruses or depression. Symptoms of long COVID are often compared to CFS. Symptoms may be a bit different for each person. The most common symptoms are:

• Sensitivity to light.

• Headache.

• Tender lymph nodes.

• Fatigue and weakness.

• Muscle and joint pain.

• Inability to focus.

• Feelings of exhaustion after putting out physical or mental energy.

• Insomnia.

• Forgetfulness.

• Mood swings.

• Confusion.

• Low-grade fever.

• Depression.

Many of these symptoms may be caused by other health problems. Always talk with your health care provider for a diagnosis.

How is chronic fatigue syndrome diagnosed?

A CFS diagnosis must rule out other possible conditions. According to the Institute of Medicine, a CFS diagnosis requires all three of these symptoms:

• Having to cut back greatly on the activities you did before the illness. Severe and chronic tiredness must have lasted for more than 6 months, and other health conditions have been ruled out. Rest does not ease these symptoms.

• Severe tiredness after physical activity. The fatigue gets worse after physical or mental stress that you could handle before the illness started.

• Sleep that doesn't refresh you.

In addition, you must have one of these symptoms:

• Trouble thinking that gets worse under pressure.

• Orthostatic intolerance. This means standing upright makes symptoms worse. Lying back down or raising (elevating) your feet may ease the symptoms. But it doesn't fully get rid of them.

How is chronic fatigue syndrome treated?

There is no known cure for CFS. Treatment is aimed at easing symptoms.

Treatment may include:

• Medicine, including corticosteroids and antidepressants.

• Activity management, including a careful balancing of rest and activity to prevent flare-ups.

• Light-intensity aerobic exercise, but not moderate to vigorously intense physical activity. 

• Dietary supplements and herbal products.

• Psychotherapy and supportive counseling.

Living with chronic fatigue syndrome

There is no known cure for CFS at this time. Dealing with the severe fatigue can be very challenging. It's important to work with your health care provider to find treatments that help you. Some people find counseling or support groups helpful.

When should I call my doctor?

Contact your health care provider if your symptoms get worse or you have new symptoms.

Key points about chronic fatigue syndrome

• Chronic fatigue syndrome is marked by profound tiredness.

• Symptoms often get worse with physical or mental activity.

• In addition to severe tiredness, symptoms include light sensitivity, headache, muscle and joint pain, trouble concentrating, mood swings, and depression.

• Treatments may include medicines, exercise, supplements, and counseling.

Next steps

Here are some tips to help you get the most from a visit to your health care provider:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your provider tells you.

• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also, write down any new instructions your provider gives you.

• Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are and when they should be reported.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is advised and what the results could mean.

• Know what to expect if you don't take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your health care provider if you have questions, especially after office hours and on weekends.