From the Guidelines
Orthostatic hypotension is diagnosed when there is a sustained reduction in systolic blood pressure of at least 20 mmHg or diastolic blood pressure of at least 10 mmHg within three minutes of standing up from a sitting or lying position, as defined by the most recent guidelines 1.
Diagnostic Criteria
The diagnosis of orthostatic hypotension requires a drop in blood pressure of ≥20/10 mmHg 1 and/or 3 min after standing following a 5-min period in the seated or lying position 1.
- The patient should be supine for at least five minutes before taking the initial blood pressure reading.
- Blood pressure readings should be taken immediately upon standing and at one-minute intervals for three minutes.
- The diagnosis also requires documentation of associated symptoms such as lightheadedness, dizziness, blurred vision, weakness, fatigue, cognitive impairment, nausea, or syncope.
Causes and Risk Factors
Orthostatic hypotension occurs due to autonomic nervous system dysfunction that impairs the body's ability to maintain adequate blood pressure during positional changes 1.
- Common causes include medications (especially antihypertensives, antidepressants, and diuretics), dehydration, prolonged bed rest, neurological disorders like Parkinson's disease, diabetes, and aging-related autonomic dysfunction.
- The condition is more prevalent in older adults, with approximately 10% of hypertensive adults and up to 50% of older institutionalized adults affected 1.
Clinical Significance
Orthostatic hypotension is a significant clinical condition that can increase the risk of falls, fractures, and mortality 1.
- Clinicians should be alert to potential symptoms of orthostatic hypotension, such as postural unsteadiness, dizziness, or fainting, especially in older hypertensive patients.
- Lying and standing blood pressures should be obtained periodically in all hypertensive individuals over 50 years old to diagnose and manage orthostatic hypotension effectively.
From the Research
Definition and Diagnosis of Orthostatic Hypotension
- Orthostatic hypotension (OH) is diagnosed when a fall in systolic blood pressure of at least 20 mm Hg and/or diastolic blood pressure of at least 10 mm Hg within 3 min of standing is recorded 2, 3, 4.
- The condition can be symptomatic or asymptomatic, and is encountered commonly in family medicine 3.
Key Elements of Orthostatic Blood Pressure Drop
- The elements of orthostatic blood pressure drop that are relevant to the definition of OH include magnitude of the drop, time to reach the blood pressure difference defined as OH, and reproducibility of the orthostatic blood pressure drop 2.
- Issues exist in each of these elements that argue for modification of the presently accepted criteria of OH, including whether one standard orthostatic test should be applied to different patient populations or if tests should be tailored to the patients' clinical circumstances 2.
Clinical Settings and Aetiologies
- Different OH thresholds may be relevant to various clinical settings, aetiologies of OH, and comorbidity 2.
- Orthostatic hypotension can occur due to various causes, including medications, non-neurogenic causes such as impaired venous return, hypovolemia, and cardiac insufficiency, and neurogenic causes such as multisystem atrophy and diabetic neuropathy 3.
- Treatment generally is aimed at the underlying cause, and a variety of pharmacologic or nonpharmacologic treatments may relieve symptoms 3, 5.