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Ask the doctor: When does fatigue indicate illness?

Anthony L. Komaroff, M.D.

Q. I feel tired all the time. How do you know if it’s a sign of something serious?

A. Boy, is that a tough question to answer in a short space. First of all, each of us feels tired if we push ourselves too hard physically, mentally, or emotionally, or if we don’t get enough sleep. People in the United States are working longer hours than ever before, so lots of people feel tired a lot of the time. So the first thing to ask yourself is if your fatigue has an obvious explanation: have you been working harder or sleeping less over the past several months?

If not, could your fatigue be caused by an illness? Many different diseases—too numerous to mention—cause fatigue. Is your recent fatigue a new experience, something that you have not experienced in the past? If so, that’s worrisome, because it could be a sign of underlying illness.

Perhaps the illness that causes fatigue more often than any others is depression. Do you feel unhappy a lot of the time, or do your friends and family say you often look “down”? Have you lost interest in things you used to love doing? If so, I’d talk to your doctor.

Sleep disorders are another common cause of fatigue. Do you have trouble falling asleep or staying asleep? Does your partner say that you are very restless at night, and sometimes seem to stop breathing for 20 seconds or more? Do you feel unrested when you awaken? Do you have a new tendency to fall asleep during the day? If so, talk to your doctor.

Along with the fatigue, do you have any new symptoms—pain, poor appetite, unplanned weight loss, a change in your bowel movements, breathlessness? New symptoms can help your doctor pinpoint an underlying disease that may be causing the fatigue.

—Anthony L. Komaroff, M.D.
Editor in Chief
Harvard Health Letter

Posted by: Dr.Health

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