Chronic Fatigue Syndrome (CFS) Symptoms
Symptoms of chronic fatigue syndrome may occur suddenly after you have a cold, bronchitis, hepatitis, or an intestinal infection. Symptoms may follow a bout of infectious mononucleosis (mono), which is caused by a virus that temporarily saps your energy. CFS can also begin after a period of high stress. Sometimes it develops more gradually, with no clear illness or other event noted as a starting point.
Unlike flu symptoms that usually go away in a few days or weeks, symptoms of CFS persist or recur in cycles for at least six months in 50% of time. CFS symptoms vary from person to person. Since 1994, the guidelines for diagnosing CFS include, in addition to a six-month history of fatigue that is not relieved with bed rest, at least four of the following eight symptoms:
- Muscle aches
- Joint pain without swelling or redness
- Trouble with short-tern memory or concentration, forgetfulness, or confusion
- Sore throat
- Tender lymph nodes
- Trouble sleeping or not feeling rested after sleep
- Worsening symptoms 24 hours or more after exercise
In addition to the eight diagnostic symptoms, patients with CFS can also suffer from:
Centers for Disease Control and Prevention website. Available at:
Devanur LD, Kerr JR. Chronic fatigue syndrome.
J Clin Virol.2006;37:139-150.
National Institute of Allergy and Infectious Diseases website. Available at:
Prins JB, van der Meer JW, Bleijenberg G. Chronic fatigue syndrome.