Chronic Fatigue Syndrome: Definition
Chronic fatigue syndrome (CFS) is a condition that causes chronic, debilitating fatigue. It continues for at least six months. The fatigue is not relieved by bed rest. People who have CFS perform at a significantly lower level compared to their activity prior to the onset of the illness.
Last reviewedNovember 2012by Michael Woods, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.