neu·ras·the·ni·a 
(nr′əs-thēnē-ə, nyr′-)
(nr′əs-thēnē-ə, nyr′-)n.
A group of symptoms, including chronic physical and mental fatigue, weakness, and generalized aches and pains, formerly thought to result from exhaustion of the nervous system and now usually considered a psychological disorder. The term is no longer in clinical use in many parts of the world.
neu′ras·thenic (-thĕnĭk) adj. & n.
neu′ras·theni·cal·ly adv.