Lightheadedness
Have you ever become lightheaded while standing up? This is a common occurrence, and it happens because your blood pools in the lower body while you are sitting, and when you abruptly stand up, it takes some time to go back to the heart and be pumped up again.
Most of the time, our bodies adjust to this change pretty fast, generally by increasing blood pressure, and we are not affected at all. But aging combined with the use of high blood pressure medications can alter how our bodies react to this and something called orthostatic hypotension. The main symptom of this is lightheadedness.
How to check for orthostatic hypotension. While you are sitting, measure your blood pressure. Then recheck it after standing. Did your blood pressure drop 10 points diastolic and 20 points or more systolic? If yes, this is a sign you have orthostatic hypotension, and you should talk to your doctor about changing your medication.