Chronic fatigue

Chronic fatigue (CF) is a symptom of many diseases, illnesses and medications. It should be distinguished from the disease called Chronic Fatigue Syndrome (CFS), of which chronic fatigue is only one of many symptoms. The two terms are not interchangeable.

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