Referring to the position of the body when standing up straight.
To an upright position (e.g., orthostatic hypotension, low blood pressure occurring in some people when they stand up).
Relating to the upright position of the body: used when describing this posture or a condition caused by it. Orthostatic hypotension, for example, is low blood pressure found in some patients when they stand upright.
Related to or resulting from an upright standing position.