Chronic Fatigue Syndrome (CFS), also known as chronic fatigue and immune dysfunction syndrome (CFIDS), post-viral fatigue syndrome, and myalgic encephalomyelitis (ME), is a chronic illness characterized by profound fatigue that is not helped by bed rest and is not directly caused by other illnesses or conditions. CFS has no known cause, and current research indicates there are probably multiple triggers such as a flu-like illness, physical trauma, emotional distress, and immunological conditions that result in the same set of symptoms. There are currently no diagnostic tests to determine if a patient is suffering from CFS. Once other possible diseases or causes are ruled out, a patient is determined to have CFS if they meet two criteria: 1) have severe chronic fatigue of six months or longer duration with other known medical conditions excluded by clinical diagnosis; and 2) concurrently have four or more of the following symptoms: substantial impairment in short-term memory or concentration; sore throat; tender lymph nodes; muscle pain; multi-joint pain without swelling or redness; headaches of a new type, pattern or severity; unrefreshing sleep; and post-exertional malaise lasting more than 24 hours.
CFS affects more than one million people in the United States, and is spread across all demographics. Women are more likely than men to suffer from CFS, and adults are more likely than children to suffer from the condition. There is no known cure for CFS, so treatment is designed to alleviate symptoms. Medications may be prescribed for pain, sleep problems, flu-like symptoms, anxiety, and depression. Patients may find that therapy and altering their lifestyles around food and activity level may help as well.