Without blood pressure, our body would not receive the oxygen and nutrients it needs to function properly. The heart has two motions – contracting and relaxing, so blood pressure is, therefore, recorded as two numbers over each other. Systolic is the actual beat of the heart and diastolic is when the heart relaxes. Systolic pressure is listed over diastolic, such as 120 over 80, which is normal blood pressure.
All sorts of conditions can have an impact on your blood pressure reading. Disease, stress, weight, and even posture can impact your blood pressure level. Blood pressure lying down verses standing has the same variations as lying down vs. sitting. Moving from a standing to a supine (lying down) position could result in different readings.
If you stand up from a sitting or lying down position and experience orthostatic hypotension, it is likely that your systolic blood pressure has decreased at least 20 mm/HG or your diastolic blood pressure has decreased at least 10 mm/HG within three minutes of standing.
It is not uncommon to feel a slight drop in blood pressure and, perhaps, experience a slight lightheaded feeling, but when the feeling lasts for a few minutes and when it happens on a regular basis, you should see a doctor. Orthostatic hypotension or postural hypotension can be a sign of a serious health problem.