What is the definition or description of: autonomic nervous system disorders?

Dysautonomia: there is an imbalance between your Sympathetic -fight or flight and Parasympathetic-house keeping nervous connections. The manifestations include organ symptoms such as, dizzy upon standing- low bp, nausea from delay stomach emptying, excess sweating or decreased sweating, chest pain, difficulty breathing-dyspnea, headaches, etc.. Special neuro work up needed; tilt test, sweat test, etc.