What Is Chronic Fatigue Syndrome?

Chronic fatigue syndrome (CFS) is an illness characterized by profound and prolonged exhaustion that is not relieved by rest and is not directly caused by other illnesses or conditions. People with CFS exhibit flu-like symptoms that do not subside in a few days or weeks. A significant characteristic of CFS is what is called "post-exertional malaise," a period of deep fatigue and exhaustion that lasts for more than 24 hours following physical exertion.

Primary Symptoms: In addition to the fatigue, the International Chronic Fatigue Syndrome Study Group identified eight primary symptoms:

• Loss of memory or concentration
• Sore throat
• Painful and mildly enlarged lymph nodes in neck or armpits
• Unexplained muscle soreness
• Pain that moves from one joint to another without swelling or redness
• Headache of a new type, pattern or severity
• Sleep disturbance
• Extreme exhaustion after normal exercise

Other Symptoms: Many CFS patients report additional symptoms which, according to the Mayo Clinic, may include:

• Abdominal pain
• Alcohol intolerance
• Bloating
• Chest pain
• Chronic cough
• Diarrhea
• Dizziness
• Dry eyes and mouth
• Earache
• Irregluar heartbeat
• Jaw pain
• Morning stiffness
• Nausea
• Night sweats
• Depression, anxiety, panic attacks
• Shortness of breath
• Tingling sensations
• Weight loss

Types of CFS: There are two reported types of chronic fatigue syndrome:

1. Sudden onset: The majority of cases start suddenly, triggered by a flu-like virus, a severe infection, another illness, or a period of great physical or emotional stress.
2. Gradual onset: Some cases begin with mild symptoms which slowly increase over time. Often gradual onset patients do not realize there is anything wrong for quite awhile. They may attribute their symptoms to stress or other mild illnesses.

Also Known As: Chronic fatigue syndrome (CFS) is or has been known by several other names, including: chronic fatigue and immune dysfunction syndrome (CFIDS), myalgic encephalomyelitis (ME), and post-viral fatigue syndrome (PVFS).