Chronic fatigue syndrome (CFS) is a disorder characterized by extreme fatigue or tiredness that doesn’t go away with rest and can’t be explained by an underlying medical condition.

CFS can also be referred to as myalgic encephalomyelitis (ME) or systemic exertion intolerance disease (SEID).

The causes of CFS aren’t fully understood yet. Some theories include viral infection, psychological stress, or a combination of factors.

Because no single cause has been identified, and because many other conditions produce similar symptoms, CFS can be difficult to diagnose.

There are no tests for CFS. Your doctor will have to rule out other causes for your fatigue when determining a diagnosis.

While CFS was previously a controversial diagnosis, it’s now widely accepted as a medical condition.

CFS can affect anyone, though it’s most common among women in their 40s and 50s. There’s currently no cure, but treatment can relieve symptoms.

Here’s what you need to know about CFS, including symptoms, treatment options, and outlook.

The cause of CFS is unknown. Researchers speculate that contributing factors may include:

It’s also possible that some people are genetically predisposed to develop CFS.

Though CFS can sometimes develop after a viral infection, no single type of infection has been found to cause CFS. Some viral infections that have been studied in relation to CFS include:

Infections caused by bacteria, including Coxiella burnetiiand Mycoplasma pneumoniae, have also been studied in relation to CFS.

The Centers for Disease Control and Prevention (CDC) has suggested that CFS may be the end stage of multiple different conditions, rather than one specific condition.

In fact, about 1 in 10 people with Epstein-Barr virus, Ross River virus, or Coxiella burnetii infection will develop a condition that meets the criteria for a CFS diagnosis.

Additionally, researchers say that those who’ve had severe symptoms with any of these three infections are at a higher risk for later developing CFS.

People with CFS sometimes have weakened immune systems, but doctors don’t know whether this is enough to cause the disorder.

People with CFS can also sometimes have abnormal hormone levels. Doctors haven’t yet concluded whether this is significant, either.

CFS is most commonly seen among people in their 40s and 50s.

Sex also plays an important role in CFS, as women are two to four times more likely to be diagnosed with CFS than men.

Other factors that may increase your risk for CFS include:

  • genetic predisposition
  • allergies
  • stress
  • environmental factors

Symptoms of CFS vary based on the individual and the severity of the condition.

The most common symptom is fatigue that’s severe enough to interfere with your daily activities. For CFS to be diagnosed, a significantly reduced ability to perform your usual daily activities with fatigue must last for at least six months. It must not be curable with bed rest.

You may also experience extreme fatigue after physical or mental activities, which is referred to as post-exertional malaise (PEM). This can last for more than 24 hours after the activity.

CFS can also introduce sleep problems, such as:

In addition, you may also experience:

  • loss of memory
  • reduced concentration
  • orthostatic intolerance (going from lying or seated to standing positions makes you lightheaded, dizzy, or faint)

Physical symptoms of CFS may include:

For some people CFS affects them in cycles, with periods of feeling worse and then better.

Symptoms may sometimes even disappear completely, which is referred to as remission. However, it’s still possible for the symptoms to return later, which is referred to as a relapse.

This cycle of remission and relapse can make it difficult to manage your symptoms, but it’s possible.

CFS is a very challenging condition to diagnose.

According to the Institute of Medicine, as of 2015, CFS occurs in about 836,000 to 2.5 million Americans. It’s estimated, however, that 84 to 91 percent are yet to receive a diagnosis.

There are no medical tests to screen for CFS. Its symptoms are similar to many other conditions. Many people with CFS don’t “look sick,” so doctors may not recognize that they indeed have a health condition.

In order to receive a CFS diagnosis, your doctor will rule out other potential causes and review your medical history with you.

They’ll confirm that you at least have the core symptoms previously mentioned. They’ll also ask about the duration and severity of your unexplained fatigue.

Ruling out other potential causes of your fatigue is a key part of the diagnosis process. Some conditions with symptoms that resemble those of CFS include:

The side effects of certain drugs, such as antihistamines and alcohol, can mimic symptoms of CFS as well.

Because of the similarities between symptoms of CFS and many other conditions, it’s important to not self-diagnose. Talk to your doctor about your symptoms. They can work with you to get relief.

There’s currently no specific cure for CFS.

Each person has different symptoms and therefore may require different types of treatment to manage the disorder and relieve their symptoms.

Work with your team of healthcare providers to create the best treatment plan for you. They can go over the possible benefits and side effects of the therapies with you.

Addressing post-exertional malaise (PEM) symptoms

PEM occurs when even minor physical, mental, or emotional exertion results in CFS symptoms becoming worse.

Worsening symptoms usually occur 12 to 48 hours after the activity and last for days or even weeks.

Activity management, also called pacing, can help balance rest and activity to avoid PEM flare-ups. You’ll need to find your individual limits for mental and physical activities, plan these activities, and then rest to stay within these limits.

Some doctors refer to staying within these limits as the “energy envelope.” Keeping diaries may help you find your personal limits.

It’s important to note that while vigorous aerobic exercise is good for most chronic conditions, people with CFS don’t tolerate such exercise routines.

Home remedies and lifestyle changes

Making some lifestyle changes may help reduce your symptoms.

Limiting or eliminating your caffeine intake can help you sleep better and ease your insomnia. You should limit or avoid nicotine and alcohol, too.

Try to avoid napping during the day if it’s hurting your ability to sleep at night.

Create a sleep routine. Go to bed at the same time every night and aim to wake up around the same time every day.

Medications

Typically, no one medication can treat all of your symptoms. Also, your symptoms may change over time, so your medications may have to as well.

In many cases, CFS can trigger or be a symptom of depression. You may need low-dose antidepressant therapy or a referral to a mental health provider.

If lifestyle changes don’t give you a restful night’s sleep, your doctor may suggest a sleep aid. Pain-reducing medication can also help you cope with aches and joint pain caused by CFS.

If medication therapy is needed, it will have to be tailored for your needs. Work closely with your doctor. There’s no one-size-fits-all treatment for CFS.

Alternative medicine

Acupuncture, tai chi, yoga, and massage may help relieve the pain associated with CFS. Always talk to your doctor before beginning any alternative or complementary treatments.

Despite increased research efforts, CFS remains a complex condition with no exact known cause and cure. Managing CFS can therefore be challenging.

You’ll likely need to make lifestyle changes to adapt to your chronic fatigue. As a result, you may experience depression, anxiety, or social isolation. You might find that joining a support group can be helpful as you’re making decisions and transitions.

CFS progresses differently in everyone, so it’s important to work with your doctor to create a treatment plan that meets your needs.

Many people benefit from working with a team of healthcare providers. This can include doctors, therapists, and rehabilitation specialists.

If you’re living with CFS, the Solve ME/CFS Initiative has resources that you may find helpful. The CDC also offers recommendations for managing and living with CFS.