The Facts

Chronic fatigue syndrome (CFS) is a condition causing persistent fatigue that lasts for at least 6 months (or longer) and isn't due to another medical condition (e.g., hypothyroidism) plus four or more specifically defined associated symptoms. It was once thought to affect only highly educated young adults who are "high achievers" or career-oriented professionals. It is now known that CFS affects people of all ages and from all walks of life. While 25% of people report being chronically fatigued, only about 0.5% of the population meet the criteria for chronic fatigue syndrome.

CFS is about 2 times more common in women than in men. Young and middle-aged people are most commonly affected, but CFS may be present in all ages, including children. It is associated with extreme and prolonged fatigue that isn't relieved by rest. People with CFS experience persistent tiredness so severe that it may prevent them from working, exercising, and enjoying life. CFS is a poorly understood condition and there is no clear consensus about its diagnosis and treatment.

CFS is also known as myalgic encephalomyelitis (ME), chronic fatigue immune dysfunction syndrome (CFIDS), or systemic exertion intolerance disease (SEID).

Causes

The exact causes of CFS are unknown, but it appears to be triggered by many different factors. Viral infections, genetic predisposition, and immune reactions are all considered possible causes of the disorder. The persistent tiredness was once attributed to a virus called the Epstein-Barr virus (this virus is responsible for mononucleosis) but the link remains scientifically unproven and is no longer considered a potential cause.

Several other potential causes of CFS are being studied including issues with sleep disruption, endocrine-metabolic dysfunction, and neurally mediated hypotension. Two-thirds or more of patients with CFS meet existing psychiatric criteria for anxiety disorders, dysthymia, or depression, but whether it is the cause or the result of CFS remains unclear. There is some evidence suggesting that CFS is an immune disorder, causing the body's defense system to function abnormally particularly in response to stress. This does not mean that the immune system is weakened, however.

It's likely that not one single factor is responsible, but rather a combination of factors. Physical activity and physical or emotional stress seems to make CFS worse. But, further research is needed to figure out its causes and to better understand this puzzling condition.

Symptoms and Complications

Extreme fatigue that lasts at least 6 months is the hallmark symptom of CFS. The onset is usually sudden. People are constantly exhausted and feel that their stamina is continuously low. Other symptoms include:

• mild fever
• sore throat
• tender neck with swollen lymph nodes
• decreased ability to concentrate
• muscle weakness and joint pain
• headaches
• memory and concentration problems
• difficulty sleeping

Problems with concentration and memory often occur. A person might have mental fogginess, impaired short-term memory, or the inability to concentrate to the point where regular activities are disrupted. Other symptoms such as gastrointestinal problems, sleep disorders, or abnormal body temperatures are also commonly reported.

Symptoms may be severe enough to interfere with work performance, leading to sick leave and extended periods of bed rest. The symptoms of CFS can last for several years, but they are usually at their worst in the early stages of the illness. Some people never return to their original energy levels. Symptoms tend to reappear during times of emotional or physical stress.

Making the Diagnosis

Doctors use two commonly accepted sets of criteria to diagnose chronic fatigue syndrome (CFS). Both require that the individual has experienced unexplained and disabling fatigue that is not relieved by rest for at least 6 months. Fatigue is considered unexplained if a thorough physical examination and medical testing have excluded other conditions that could cause fatigue.

Other criteria necessary to diagnose chronic fatigue syndrome include mental changes such as poor memory, muscle or joint pains, headaches, tender lymph nodes, unrefreshing sleep, and worsening of symptoms after exercise.

Treatment and Prevention

Although there are no recommended or proven treatments to date, management of CFS includes reassurance and support of the condition and how things will improve with time. It is difficult to predict when and how much someone with CFS will improve, since this varies a great deal between individuals.

Cognitive behavioral therapy and exercise (starting slow and increasing over time) appear to produce the most benefit. A doctor will likely combine a number of different treatments aimed at addressing your specific symptoms, including:

• medical intervention and medications
• alternative therapies
• psychotherapy (cognitive behavioral therapy)
• physical and lifestyle adjustments

Since no medication has been specifically proven to cure CFS, medications are used to treat some of the symptoms that are seen with CFS. For depression, antidepressants such as selective serotonin reuptake inhibitors (SSRIs; e.g., paroxetine, sertraline)* or tricyclic antidepressants (TCAs; e.g., amitriptyline, imipramine) may be used. Anti-anxiety medications such as lorazepam may be used to treat anxiety. Sleeping pills, such as zopiclone, may be used to treat certain sleep disorders, though referral to a sleep specialist may be necessary. Nonsteroidal anti-inflammatory drugs (NSAIDs) are used for headaches, fever, and general aches and pains. Fatigue and concentration problems can be treated with methylphenidate (a stimulant medication used for attention disorders).

CFS can sometimes go away on its own. Medications should therefore be tried for short periods and then stopped, and the person's status should be reassessed before continuing with medication treatment.

Some people seek alternative therapies, including massage, acupuncture, herbal products, and dietary supplements. Herbal preparations that have been used by some people with CFS include astragalus, borage seed oil, bromelain, comfrey, echinacea, garlic, ginkgo biloba, ginseng, primrose oil, quercetin, St. John's wort, and shiitake mushroom extract.

The value of alternative remedies is questionable. With few exceptions, most of these remedies haven't been shown to be effective for treating CFS patients. Many people believe that just because herbal products are "natural" they're also safe, which is not always true. Besides containing an active compound that may have medicinal properties, unrefined plant preparations also have other substances that can harm you. In addition, many dietary supplements are not regulated by the Food and Drug Administration (FDA), meaning there may be inconsistencies with dosing of the active component. Comfrey and high doses of ginseng, for example, are known to have harmful effects. As well, herbal preparations and dietary supplements can interfere with other medications you may be taking or cause side effects.

Before taking alternative remedies, talk to a doctor or pharmacist about what's safe and appropriate for your specific situation.

Psychotherapy is another strategy that can help people with CFS and their families cope with the symptoms of CFS. Cognitive behavioral therapy may help alleviate some of the distress and concerns about CFS and its affects on your work and personal life.

Physical and lifestyle changes may also be recommended. Prolonged lack of exercise can exacerbate physical weakness. A graded exercise regimen can be a means of restoring some of the loss of energy and stamina. "Graded" exercise means starting exercise slowly and gradually increasing the amount and intensity over time.

Learning ways to manage energy levels is important; for instance, overexertion during periods of good health can lead to a return of symptoms. Finding ways to cope and deal with physical and emotional stresses can help prevent a return of CFS symptoms.

*All medications have both common (generic) and brand names. The brand name is what a specific manufacturer calls the product (e.g., Tylenol®). The common name is the medical name for the medication (e.g., acetaminophen). A medication may have many brand names, but only one common name. This article lists medications by their common names. For more information on brand names, speak with your doctor or pharmacist.