- Fatigue (either physical, mental or both) is a symptom that may be difficult for the patient to describe and words like lethargic, exhausted and tired may be used.
- Taking a careful and complete history is the key to help making the underlying diagnosis of the cause for the symptom of fatigue. However, in about a third of patients the cause is not found and the diagnosis is not known.
- There are numerous causes of fatigue symptoms. Examples of some treatable causes of fatigue include anemia, diabetes, thyroid disease, heart disease, COPD and sleep disorders (Table).
- Long lasting complaints of fatigue do not equate to chronic fatigue syndrome. Specific criteria as set by the CDC need to be met to make that particular diagnosis.