Definition of Orthostatic Hypotension
Orthostatic hypotension is defined as a sustained decrease in systolic blood pressure ≥20 mmHg and/or diastolic blood pressure ≥10 mmHg within 3 minutes of standing from a supine position. 1
Classical Definition and Variants
Orthostatic hypotension (OH) has several recognized variants:
Classical OH: Sustained decrease in systolic BP ≥20 mmHg and/or diastolic BP ≥10 mmHg within 3 minutes of standing, or a sustained decrease in systolic BP to an absolute value <90 mmHg 1
Initial (immediate) OH: BP decrease >40 mmHg systolic and/or >20 mmHg diastolic within 15 seconds of standing, with spontaneous return to normal within 40 seconds 1
Delayed OH: Sustained reduction of systolic BP ≥20 mmHg or diastolic BP ≥10 mmHg that takes >3 minutes of upright posture to develop 1
Some guidelines also consider a fall in systolic blood pressure of 30 mmHg as significant for orthostatic hypotension diagnosis 2.
Diagnostic Measurement Protocol
For accurate diagnosis, blood pressure should be measured:
- After 5 minutes in the supine position
- At 1 minute after standing
- At 3 minutes after standing 1
Both blood pressure and heart rate should be recorded at each measurement point to help distinguish between neurogenic and non-neurogenic causes 1:
- Neurogenic OH: Blunted orthostatic heart rate increase (usually <10 beats per minute)
- Non-neurogenic OH: Preserved or enhanced orthostatic heart rate increases
Clinical Significance
Orthostatic hypotension is associated with:
- Increased all-cause mortality (up to 50% increase in relative risk) 3
- Increased cardiovascular disease risk 1
- Higher risk of falls and syncope 3
- Reduced quality of life 3
Common Symptoms
Symptoms of orthostatic hypotension result from organ hypoperfusion and include:
- Dizziness and lightheadedness
- Visual disturbances
- Weakness and fatigue
- Palpitations and sweating
- Neck and shoulder pain (coat hanger syndrome)
- Hearing disturbances
- Precordial pain 1, 3
Common Pitfalls in Diagnosis
- Not monitoring long enough to detect delayed OH
- Failing to account for supine hypertension
- Not considering the absolute BP level
- Overlooking pseudohypertension in elderly patients 1
When standard orthostatic vital sign measurements are nondiagnostic but clinical suspicion remains high, head-up tilt-table testing can aid in confirming the diagnosis 3, 4.
Orthostatic hypotension is particularly common in older adults (prevalence of approximately 20%) and in patients with conditions such as Parkinson's disease, multiple system atrophy, diabetes, and autonomic neuropathies 1, 3.