Table.

Conditions, Mechanisms, and Impact of Hypertension Treatment on Various Clinical Presentations of OH

Diagnosis	Mechanism	Predominant pattern	Effect of hypertension treatment	Related conditions
Classic OH	Autonomic dysfunction	Low standing BP with or without supine hypertension Often symptomatic	Worse upright hypotension; improved supine hypertension	Parkinson disease, pure autonomic failure
Hypertensive OH	Reduced diastolic filling due to left ventricular hypertrophy; arterial stiffness	High supine/seated BP, normal standing BP Often asymptomatic	Reduced incidence with improved BP regulation	Hypertension, left ventricular hypertrophy, atherosclerotic disease
Pseudo-OH, threshold effect* (see Supplemental Figure)	Similar percent change at higher BP exceeds the BP threshold used to define OH	High supine/seated BP Asymptomatic	Reduced incidence with lower resting BP	Hypertension
Pseudo-OH, measurement error† (see Figure 2)	Greater measurement error with higher resting BP can cause the appearance of a large change in BP if the first error goes opposite to the second error.	Transient/nonreproducible Asymptomatic	Lower BP variability with lower resting BP	Hypertension, BP lability

BP indicates blood pressure; and OH, orthostatic hypotension.

^*It has been recommended to use a systolic change threshold of 30 mm Hg among patients with hypertension to address this concern.

^†This issue also affects orthostatic hypertension.