Fatigue can be described as the lack of energy and motivation (both physical and mental). This is different than drowsiness, a term that describes the need to sleep. Often a person complains of feeling tired and it is up to the health care professional to tell fatigue from drowsiness, though both can occur at the same time.
Aside from drowsiness, other symptoms can be confused with fatigue including shortness of breath with activity and muscle weakness. Again, all these symptoms can occur at the same time. Also, fatigue can be a normal response to physical and mental activity; in most normal individuals it is quickly relieved by reducing the activity.
Everyone feels tired now and then. Sometimes you may just want to stay in bed. But, after a good night’s sleep, most people feel refreshed and ready to face a new day. If you continue to feel tired for weeks, it’s time to see your doctor. He or she may be able to help you find out what’s causing your fatigue and recommend ways to relieve it.