Chronic fatigue

The "Name" Chronic Fatigue is in reality a symptom of many diseases, illnesses and medications. Chronic Fatigue Syndrome is a grossly misnamed disease. The two are not interchangeable.

Chronic Fatigue vs. Chronic Fatigue Syndrome
About.com Health FMS/ME/CFS has two blogs discussing the difference. One by Adrienne Dellow: "Chronic Fatigue vs. Chronic Fatigue Syndrome - One's a Symptom, One's a Disease" and another by Carol Eustice: "Chronic Fatigue Versus Chronic Fatigue Syndrome - What's the Difference?