Chronic fatigue syndrome

Chronic fatigue syndrome (CFS) is a debilitating condition marked by profound, long-lasting fatigue and multiple other symptoms such as joint pain and muscle pain. A syndrome is not a disease but rather a cluster of symptoms. CFS often starts abruptly but can develop gradually. The cause is unknown, but CFS is believed not to be contagious or fatal.

People with chronic fatigue syndrome experience disruption in one or more aspects of their life, such as work, self-care and family life. The name is misleading because it does not indicate the severity of the disabling symptoms, according to the National Women’s Health Resources Center and CFS support groups.

The syndrome has been controversial, with disagreements over diagnostic criteria, treatment and even the existence of CFS. Patients have sometimes been described disparagingly as having “yuppie flu,” faking a condition or being mentally ill. However, recent research released by the U.S. Centers for Disease Control and Prevention (CDC) supports CFS as having a biological basis. Some research has suggested genetics plays a role.

The U.S. National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) emphasizes that chronic fatigue syndrome is not the same thing as chronic fatigue, which is also a symptom of fibromyalgia, rheumatoid arthritis, systemic lupus erythematosus (SLE) and other conditions.

Chronic fatigue syndrome can strike anyone but is most common in young and middle-age women. It is generally estimated that about 900,000 Americans have a CFS-like condition, according to the National Women’s Health Resources Center. The CDC puts the figure at roughly 500,000. The International Association for Chronic Fatigue Syndrome estimates that 500,000 to 800,000 Americans have CFS, 85 percent of them still undiagnosed. According to the Chronic Fatigue and Immune Dysfunction Syndrome Association of America, CFS is much more common in women than better-known conditions such as HIV infection or lung cancer.

Chronic fatigue syndrome was named in the 1980s, but the condition or similar disorders have been known by other names for centuries. It used to be known as chronic Epstein-Barr because it was once blamed on the Epstein-Barr virus. Current alternate terms for CFS include chronic fatigue and immune dysfunction syndrome (CFIDS) and postviral fatigue syndrome.

Scientists do not know what causes chronic fatigue syndrome (CFS). It was once thought to be caused by infection with Epstein-Barr virus (EBV) or another virus and used to be referred to as chronic EBV. However, it is now believed that CFS cannot result from infection with any one known human pathogen, though infectious agents may play a role in some cases of CFS, according to the National Center for Infectious Diseases.

Some CFS patients have signs of autoimmune diseases, such as autoantibodies (immune system proteins that mistakenly attack the body’s healthy tissues). However, tissue damage characteristic of autoimmune disorders has not been described in people with CFS.

Several studies indicate that the central nervous system has a role in CFS. For example, CNS dysfunction may impair the immune system or inhibit the release of pain-relieving hormones such as cortisol. More research will be needed to establish a link.

In addition to researching possible roles of the immune and nervous systems, scientists are studying other possible factors, including genetic predisposition, stress, metabolic disturbances, hormones and environment.

According to the National Women’s Health Resource Center, one-third of cases follow a symptomatic respiratory, stomach or other acute infection, and other cases develop after physical or emotional trauma such as surgery, a car accident or the death of a loved one. Some research has linked a sedentary lifestyle to increased risk of CFS.

The primary known risk factors for chronic fatigue syndrome are sex and age. Three to four times as many women as men have CFS, and the condition seems to be most common in women in their 40s, according to the National Women’s Health Resource Center. The condition can occur at any age and has also been described in young adults and adolescents.

The primary indicator of chronic fatigue syndrome (CFS) is severe fatigue that has lasted for months. Individuals often feel exhausted even after mild or moderate physical activity. Other common signs and symptoms include:

• Difficulties with memory or concentration
• Muscle or joint pain
• Insomnia or other problems with sleep
• Headaches
• Sore throat
• Tender, painful lymph nodes
• Stress, anxiety, depression or panic

• Abdominal pain or bloating
• Chest pain, irregular heartbeat or shortness of breath
• Diarrhea
• Dizziness
• Dry eyes and mouth
• Ear pain
• Intolerance for alcohol
• Jaw pain such as TMJ disorder
• Morning stiffness
• Nausea
• Night sweats
• Tingling
• Unexplained weight loss

A physician seeing a patient who may have chronic fatigue syndrome (CFS) will typically review the patient's medical history and perform a physical examination focusing on the joints, lymph nodes and other body parts affected. Physicians often assess mental status by asking questions or using an oral or written test.

Blood tests and urine tests may be ordered to identify or rule out other possible sources of fatigue, such as anemia (insufficient number of red blood cells). Tests suggested by the U.S. Centers for Disease Control and Prevention (CDC) for screening patients for chronic fatigue syndrome include:

• Complete blood count and electrolytes, to indicate many possible underlying diseases
• Sedimentation rate, to detect inflammation
• Waste product tests, to detect kidney disease and other disorders
• Alanine aminotransferase (ALT) and globulin, to detect liver diseases
• Albumin, to detect malnutrition, liver disease, kidney disease or other problems
• Calcium, to detect cancer and other disorders
• Phosphorus, to detect kidney failure and other disorders
• Glucose, to detect diabetes
• Total protein, to detect dehydration
• Thyroid stimulating hormone (TSH), to detect thyroid disorders
• Urinalysis, to detect kidney diseases, systemic lupus erythematosus (SLE) and many other disorders

• Have severe, chronic fatigue for six months for more, with other known causes ruled out by clinical diagnosis
• Have four or more of the following symptoms for the previous six months or longer:
  • Substantially impaired concentration or short-term memory
  • Sore throat
  • Tenderness in the lymph nodes of the armpits or neck
  • Muscle pain
  • Multiple joint pains without swelling or redness
  • Headaches of a new type, pattern or severity
  • Lack of refreshment from sleep
  • Discomfort for more than 24 hours after exertion

Scientists are trying to develop diagnostic techniques specific to chronic fatigue syndrome. Spinal taps have revealed a group of proteins found in the cerebrospinal fluid of people with CFS but not in healthy individuals. These findings are not sensitive or specific at this time but could eventually lead to a test that allows earlier diagnosis and treatment.

The CDC advises against trying to diagnose CFS with experimental serologic and immunologic tests, such as retrovirus tests. Testing for Epstein-Barr virus (EBV) was once used in diagnosing chronic fatigue syndrome because EBV was considered a likely cause, but scientists have learned that many cases of CFS have no link to this virus.

There is no known cure for chronic fatigue syndrome (CFS). Treatment focuses on relieving symptoms and helping the patient adapt. The treatment plan developed with the physician can vary greatly, depending on the individual’s needs, symptoms and general health. The treatment plan may include:

Medications

Patients are advised to ask their physician about the benefits and side effects of medications. Drugs that have been used in the treatment of CFS include:

• Aspirin, naproxen or other NSAIDs (nonsteroidal anti-inflammatory drugs) to reduce pain and inflammation
• Analgesics such as acetaminophen to relieve pain
• Antidepressants, such as tricyclics and serotonin reuptake inhibitors, to improve sleep and relieve malaise
• Anxiolytic agents to reduce anxiety
• Stimulants to reduce daytime lethargy

In addition, researchers are studying new drugs to treat CFS.

AzathioprineFluoxetinDoxepinImipramineAtenololZolpidemFludrocortisoneCarisoprodolAlprazolam

There is no known way to prevent chronic fatigue syndrome, but people can avoid exacerbations by practice good habits (exercise, diet, sleep) as described above.

In addition, avoiding excess standing and heat may help. Many people with CFS experience lightheadedness or increased fatigue if they stand for long periods or spend time in warm places, according to the CDC. Such individuals are advised to avoid triggers such as long showers, saunas and tasks that require prolonged standing.