Why Am I Constantly Tired?

Could It Be Chronic Fatigue Syndrome?

So you're getting at least eight hours of quality sleep a night, eating healthfully, and trying to exercise for at least 30 minutes on most days of the week -- and still you're exhausted? Talk to your physician. More serious cases of feeling tired could be an indication of chronic fatigue syndrome.

The symptoms of CFS are similar to those of many ailments, and researchers don't know exactly what causes it -- theories range from a virus to a malfunctioning immune system. As a result, no one is certain how many people have it. If you do have CFS, symptoms such as headache, tender lymph glands, sore throat, fatigue and weakness, muscle and joint pain, "unrefreshing" sleep, and the inability to concentrate may come and go or remain constant for six months, in which case you should see a physician.

Originally published in FITNESS magazine. Updated March 2007.