Excessive tiredness or
Fatigue means lacking energy or strength and is a very common symptom.
However, the term in common usage may mean many things, including drowsiness
(sleepiness), lethargy, tiredness, malaise, listlessness, or weakness (including
muscular weakness). Sometimes it is hard to know exactly whether you are tired,
weak, fatigued, or have other symptoms. Nevertheless, any type of fatigue can
indicate a serious medical condition and needs prompt medical investigation