Dysautonomia literally means dysfunction of the autonomic nervous system. The
autonomic nervous system is the master regulator of all unconscious
organ function throughout the body. It is involved in the control of
heart rate, blood pressure, temperature, respiration, digestion and
other vital functions. Dysfunction of the autonomic nervous system can
produce the apparent malfunction of the
organs it regulates. For this reason, dysautonomia patients often
present with numerous, seemingly unrelated maladies.
Orthostatic intolerance is present when patients experience symptoms such as
lightheadedness, palpitations, and tremulousness during standing. Many
patients also note other symptoms with upright posture: visual changes,
discomfort in the head or neck, throbbing of the head, poor
concentration, tiredness, weakness, and occasionally fainting. Patients
can be severely impaired by these symptoms and signs, such as a
bluish-red suffusion of skin in the lower extremities on standing,
which are relieved by lying down
Postural Orthostatic Tachycardia Syndrome
Often more simply referred to as postural tachycardia syndrome, or
POTS, this disorder is characterized by the body's inability to make
the necessary adjustments to counteract gravity when standing up. The
defining symptom of POTS is an excessive heart rate increment upon
standing. However, as you will discover, there are a multitude of other
symptoms that often accompany this syndrome. As such, POTS can be a
difficult disorder to detect and understand.
Neurocardiogenic Syncope (NCS)
Sometimes referred to as neurally mediated syncope or vasovagal
syncope, this disorder is characterized by an episodic fall in blood
pressure and/or heart rate that results in fainting (Robertson, 2002).
Pure Autonomic Failure (PAF)
A degenerative disease of the peripheral nervous system characterized
by a markedÂ all in blood pressure upon standing (orthostatic
hypotension). The orthostatic hypotension leads to symptoms associated
with cerebral hypoperfusion, such as dizziness, fainting, visual
disturbances and neck pain (Mathias, Mallipeddi & Bleasdale-Barr,
1999). Other symptoms such as chest pain, fatigue and sexual
dysfunction may also occur. Symptoms are worse when standing and are
sometimes relieved by sitting or lying flat.
References 1. Mathias, C. J., Mallipeddi, R. and Bleasdale-Barr, K.
(1999). Symptoms associated with orthostatic hypotension in pure
autonomic failure and multiple systemÂ atrophy. Journal of
Neurology, 246, (10), 893-898. 2. MEDLINEPlus Heath Information.
(2003). Multiple System Atrophy. Retrieved September 8, 2003 from: