<P> Orthostatic hypotension , also known as postural hypotension , occurs when a person 's blood pressure falls when suddenly standing up from a lying or sitting position . It is defined as a fall in systolic blood pressure of at least 20 mm Hg or diastolic blood pressure of at least 10 mm Hg when a person assumes a standing position . It occurs predominantly by delayed constriction of the lower body blood vessels , which is normally required to maintain an adequate blood pressure when changing position to standing . As a result , blood pools in the blood vessels of the legs for a longer period and less is returned to the heart , thereby leading to a reduced cardiac output . Mild orthostatic hypotension is common and can occur briefly in anyone , although it is prevalent in particular among the elderly and those with known low blood pressure . Severe drops in blood pressure can lead to fainting , with a possibility of injury . </P>
<P> Orthostatic hypotension , also known as postural hypotension , occurs when a person 's blood pressure falls when suddenly standing up from a lying or sitting position . It is defined as a fall in systolic blood pressure of at least 20 mm Hg or diastolic blood pressure of at least 10 mm Hg when a person assumes a standing position . It occurs predominantly by delayed constriction of the lower body blood vessels , which is normally required to maintain an adequate blood pressure when changing position to standing . As a result , blood pools in the blood vessels of the legs for a longer period and less is returned to the heart , thereby leading to a reduced cardiac output . Mild orthostatic hypotension is common and can occur briefly in anyone , although it is prevalent in particular among the elderly and those with known low blood pressure . Severe drops in blood pressure can lead to fainting , with a possibility of injury . </P>
low blood pressure that occurs upon standing up is known
low blood pressure that occurs upon standing up is known
Orthostatic hypotension postural hypotension
Orthostatic hypotension postural hypotension