Diastolic Blood Pressure

* What are the possible factors could cause the actual results of making inaccurate blood pressure, other than the arms are not at the heart?

* What are the systolic and diastolic average for someone when they are standing, sitting, lying down, and upside down?

If they have a health problem such as atrial fibrillation or hypotensive for some reason their blood pressure may drop significantly in standing or sitting. Yet in the adult healthy blood pressure should remain stable at around 120/80 regardless of position. The only sources of error, I can imagine the noise artifact created by the environment, the stethoscope tubes rubbing together, if the patient is moving their arms or fingers, or if clothing around the arm patients (although I debate this theory)