<unk>  is a medical condition consisting of a sudden and abrupt increase in blood pressure (BP) when a person stands up.<unk>  is diagnosed by a rise in systolic BP of 20 mmHg or more when standing.<unk>  diastolic hypertension is a condition in which the diastolic BP raises to 98 mmHg or over in response to standing, but this definition currently lacks clear medical consensus, so is subject to change.<unk>  involving the systolic BP is known as systolic<unk> . If affecting an individual's ability to remain upright,<unk>  is viewed as a form of<unk>  intolerance. The body's inability to regulate BP can be a type of dysautonomia. Baroreflex and autonomic pathways normally ensure that blood pressure is maintained despite various stimuli, including postural change. The precise mechanism of<unk>  remains unclear, but alpha-adrenergic activity may be the predominant pathophysiologic mechanism of<unk>  in elderly hypertensive patients. Other mechanisms are proposed for other groups with this disorder. A prevalence of 1.1% was found in a large population study. The risk of<unk>  has been found to increase with age, with it being found in 16.3% of older hypertensive patients.
Orthostatic hypertension
Labile hypertension
Paroxysmal hypertension
Hypertensive urgency
Benign hypertension
Systolic hypertension
Secondary hypertension
White coat hypertension