[Orthostatic hypotension: focus on a common pathology sometimes misknowned].

Orthostatic hypotension is a frequent pathology especially in older adults and inhospital patients. Prevalence is increasing with age, and is about 30 % of patients older than 65 years. Orthostatic hypotension is defined as a fall in blood pressure of at least 20 mmHg systolic or 10 mmHg diastolic when standing or during head-up tilt testing.