How do you diagnose orthostatic hypotension?

Diagnosis of Orthostatic Hypotension

Orthostatic hypotension (OH) is diagnosed by measuring a reduction in systolic blood pressure ≥20 mmHg or diastolic blood pressure ≥10 mmHg within 3 minutes of standing from a supine position. 1, 2

Diagnostic Procedure

Standard Orthostatic Blood Pressure Measurement

1. Patient preparation:

   • Have patient rest in supine position for 5 minutes
   • Use a validated and calibrated blood pressure device 1

2. Measurement sequence:

   • Measure baseline blood pressure and heart rate after 5 minutes of rest in supine position
   • Ask patient to stand
   • Measure blood pressure and heart rate at 1 minute and 3 minutes after standing 1
   • Document any symptoms that occur during standing

3. Alternative approach (if patient cannot stand safely):

   • Head-up tilt table testing at an angle of at least 60 degrees 2

Interpretation of Results

• Classical orthostatic hypotension: BP starts to decrease immediately after standing with a "concave" curve pattern 3
• Delayed orthostatic hypotension: BP decreases more gradually, with variable patterns of decrease 3
• Neurogenic orthostatic hypotension (NOH): Characterized by BP drop with blunted heart rate response (usually <10 bpm) 1

Symptoms to Document

• Lightheadedness or dizziness
• Visual disturbances
• Weakness or fatigue
• Neck and shoulder pain ("coat hanger" syndrome)
• Syncope or near-syncope
• Cognitive slowing
• Headache
• Chest pain or dyspnea 2

Important Diagnostic Considerations

• Timing: OH must occur within 3 minutes of standing to meet diagnostic criteria 1, 2
• Symptom correlation: Document whether symptoms correlate with BP drops, though many patients may be asymptomatic 4
• Diurnal variation: Consider ambulatory BP monitoring to identify abnormal diurnal patterns 1
• Heart rate response: Assess heart rate changes during position change to help differentiate neurogenic from non-neurogenic causes 1
  • Minimal increase in heart rate (<10 bpm) suggests neurogenic OH
  • Normal compensatory increase in heart rate suggests non-neurogenic causes

Special Diagnostic Situations

• When standard testing is non-diagnostic but clinical suspicion remains high:

  • Consider head-up tilt table testing 2, 5
  • Perform testing at different times of day (morning OH may be more pronounced)
  • Test after meals to detect postprandial hypotension

• For elderly patients:

  • Be particularly vigilant as prevalence reaches 20% in older adults 2
  • Review medication list thoroughly as polypharmacy is a common cause 1

Common Pitfalls to Avoid

1. Inadequate rest period: Ensure full 5 minutes of rest before baseline measurement
2. Improper technique: Use appropriately sized cuff and validated device
3. Missing delayed OH: Extend monitoring beyond 3 minutes if clinically indicated
4. Failure to assess heart rate: Always document heart rate changes alongside BP
5. Overlooking medications: Review all medications that may cause or worsen OH
6. Ignoring asymptomatic OH: Even asymptomatic OH is associated with increased cardiovascular risk and mortality 2, 4

By following this structured approach to diagnosing orthostatic hypotension, clinicians can identify this common condition that significantly impacts morbidity, mortality, and quality of life.