Some fatigue in life is to be expected. But if you experience a marked change in your energy level or your fatigue persists despite adequate rest, see your doctor. Being tired all the time may be a sign of an underlying medical problem. The tired life Stress and anxiety. If you're burning the candle at both ends, you're going to feel it.
Anxiety also can cause fatigue.
If worries are keeping you from relaxing, you're likely not getting the rest you need. Stress Management Planner Lack of sleep. One of the chief causes of fatigue is lack of sleep. You may not go to bed early enough. Or, more likely, you go to bed but can't sleep well.