Chronic fatigue is a condition that you have got fatigue and tiredness for a long time. Sometimes an underlying disease can be found. Sometimes, it cannot be found. If you have extreme fatigue but no reason can be found, your doctor may say you have got chronic fatigue symdrome. If you have been feeling fatigue for only several days or weeks, use Fatigue (acute fatigue) instead.
By answering questions about your condition, you can find the causes.