Orthostatic hypotension occurs when intravascular volume is significantly decreased or there is impairment in autonomic reflexes. Symptoms can include dizziness, lightheadedness, or syncope. It is defined as a blood pressure decrease of at least 20 mm Hg systolic or at least 10 mm Hg diastolic after 2-5 minutes of standing. The condition is generally benign.

Orthostatic hypotension is more common in the elderly than in younger patients. Its underlying cause is a failure of the autonomic nervous system to appropriately vasoconstrict the peripheral vasculature in response to standing. Orthostatic hypotension may be caused by diseases that disrupt the autonomic nervous system, such as Parkinson disease, diabetes, amyloidosis, or familial dysautonomia. Orthostatic hypotension is also a common side effect of certain medications, such as antihypertensives and diuretics.

Orthostatic hypotension can be treated with lifestyle modifications and medications that increase vasoconstriction or intravascular volume.