Fatigue is a feeling of tiredness, exhaustion, or lack of energy. You may feel mildly fatigued because of overwork, poor sleep, worry, boredom, or lack of exercise. Most causes of fatigue will resolve in time without requiring a visit to the doctor. If your fatigue is not improving with rest, or out of character from what you are accustomed to it is important to seek further medical evaluation by your health care provider.

More: continued here