Table 1.

Characteristics of neurogenic and non-neurogenic orthostatic hypotension

Modified from [4]

	Non-neurogenic orthostatic hypotension	Neurogenic orthostatic hypotension
Frequency	Frequent (particularly in the elderly)	Rare (<200,000 in the US)
Onset	Variable	Chronic in synucleinopathies. Acute or sub-acute in immune-mediated neuropathies and ganglionopathies
Causes	Intravascular volume loss (e.g., dehydration, anemia) Antihypertensive medications Blood pooling (e.g., large varicose veins, skeletal muscle atrophy) Physical deconditioning, Advanced heart failure Adrenal insufficiency	Defective norepinephrine release from sympathetic post-ganglionic neurons upon standing up
Prognosis	Resolves when underlying cause is corrected	Chronic disorder
Increase in heart rate upon standing	Pronounced (usually >25 bpm)	Mild or absent (usually <20 bpm)
Blood pressure overshoot (phase 4) in Valsalva maneuver	Present	Absent
Increase in plasma norepinephrine levels upon standing	Normal or enhanced (at least ×2)	Reduced or absent (less than ×2)
Other symptoms of autonomic failure	No	Constipation Erectile dysfunction (men) Urinary abnormalities Sweating abnormalities
Concomitant neurological deficits	None (or if present, they are not related to OH)	None Parkinsonism Cerebellar signs Cognitive impairment Sensory neuropathy