effort syndrome

orthostatic intolerance

A condition (OMIM:604715) characterised by lightheadedness, fatigue, altered mentation, syncope and tachycardia upon assuming an upright position, and markedly elevated serum norepinephrine. 
Molecular pathology
Defects in SLC6A2, which encodes a member of the sodium:neurotransmitter symporter that regulates norepinephrine homeostasis, are a cause of orthostatic intolerance.

effort syndrome

Unusual or unexpected fatigue with exertion. The fatigue is increased by mild exertion and may be more pronounced in the morning. See: chronic fatigue syndrome

effort syndrome

See DA COSTA SYNDROME.