Orthostatic Hypotension Diagnostic Criteria
A positive orthostatic hypotension is defined as a sustained decrease in systolic blood pressure ≥20 mmHg OR diastolic blood pressure ≥10 mmHg within 3 minutes of standing. 1, 2, 3
Standard Diagnostic Thresholds
The diagnostic criteria require BOTH of the following components:
Magnitude of drop: Systolic BP decrease ≥20 mmHg OR diastolic BP decrease ≥10 mmHg (either threshold alone is sufficient for diagnosis) 1, 2, 3, 4
Timing: The BP drop must occur within 3 minutes of standing or head-up tilt to at least 60 degrees 1, 2, 3
Alternative criterion: A drop in systolic BP to an absolute value <90 mmHg within 3 minutes also confirms the diagnosis, regardless of the magnitude of change 2, 3, 5
Special Populations
- Patients with supine hypertension: A systolic BP drop ≥30 mmHg should be considered diagnostic, even if it doesn't meet the standard 20 mmHg threshold 2, 3, 5
Proper Measurement Technique
To ensure accurate diagnosis, follow this protocol:
Have the patient rest supine for 5 minutes before obtaining baseline BP and heart rate 2, 3, 6
Measure BP in both arms at the initial visit; use the arm with higher readings (if difference >10 mmHg) for all subsequent measurements 2
Obtain standing measurements at 1 minute AND 3 minutes after the patient stands 2, 5
Use a validated, calibrated device with appropriate cuff size based on arm circumference 2
Maintain the arm at heart level during all measurements 2
Subtypes Based on Timing
Understanding the timing pattern helps differentiate orthostatic hypotension subtypes:
Classical orthostatic hypotension: BP drop occurs within 3 minutes and is sustained 1, 3, 5
Initial orthostatic hypotension: Transient BP decrease >40 mmHg systolic and/or >20 mmHg diastolic within the first 15 seconds of standing, with rapid spontaneous recovery 1, 2, 3
Delayed orthostatic hypotension: BP drop meeting diagnostic criteria but occurring beyond 3 minutes of standing (up to 10 minutes) 2, 3, 5
Clinical Pearls and Common Pitfalls
Avoid measuring immediately after standing: This captures only initial BP changes and misses the sustained decreases required for classical orthostatic hypotension diagnosis, leading to false-negative results 2
Consider extended monitoring: If clinical suspicion is high but the 3-minute test is negative, extend standing time to 10 minutes to detect delayed orthostatic hypotension, which carries a 29% ten-year mortality rate 2
Heart rate response distinguishes etiology: Neurogenic orthostatic hypotension shows a blunted HR increase (usually <10 bpm), while non-neurogenic causes show preserved or enhanced HR increase 5
Symptoms depend on absolute BP level: The severity of symptoms correlates more with the absolute BP reached than with the magnitude of the drop 2, 5
Population data on timing: Only 46% of individuals with orthostatic hypotension demonstrate it within the first 3 minutes, 15% between 3–10 minutes, and 39% only after 10 minutes, emphasizing the need for proper timing in measurements 2