Definition of Orthostatic Hypotension
Orthostatic hypotension is defined as a drop in systolic blood pressure of ≥20 mm Hg or diastolic blood pressure of ≥10 mm Hg within 3 minutes of standing from a supine position. 1, 2
Standard Diagnostic Criteria
The 2017 ACC/AHA/HRS guidelines provide the authoritative definition that should be used in clinical practice 1, 2. This hemodynamic threshold applies regardless of whether symptoms are present or absent.
Important Subtypes to Recognize
The guidelines distinguish several clinically relevant subtypes that affect management 1, 2:
Classic OH: The standard definition—sustained BP reduction of ≥20/10 mm Hg within 3 minutes of standing
Initial (Immediate) OH: Transient BP decrease within 15 seconds after standing, typically associated with presyncope or syncope
Delayed OH: Sustained BP reduction of ≥20/10 mm Hg (or ≥30 mm Hg systolic in patients with supine hypertension) that takes >3 minutes to develop, with gradual BP fall
Neurogenic OH: OH due to autonomic nervous system dysfunction rather than environmental triggers like dehydration or medications
Measurement Technique
To properly diagnose OH, measure blood pressure after 5 minutes supine, then at 1 and 3 minutes after standing 3. If the patient cannot stand safely or initial testing is negative despite high clinical suspicion, head-up tilt table testing at ≥60 degrees is recommended 1, 3.
Critical Clinical Caveat
The presence or absence of symptoms does not define orthostatic hypotension—the diagnosis is based solely on the blood pressure criteria. Many patients with OH are asymptomatic or have atypical symptoms 4. However, symptomatic OH typically warrants more aggressive management focused on improving quality of life and reducing fall risk 5, 6.