Q: In the sitting position my BP is 135/80, lying position it is 117/60. Why the drastic difference? Thank you.
A: The heart is a pump. It takes less effort to pump blood to your brain when you are lying down because your head is about the same level as your heart. When you stand up, your head is much higher than your heart.
The heart has to pump harder to get blood to your brain so blood pressure is higher. It is well known that blood pressure varies with position. This is why blood pressure at the doctor’s office is taken while you are sitting in a chair with your arm at the level of your heart.