When I measure by BP I always do it the same way at the same time of day. First thing in the morning before getting any water on my face (can you save dive response) laying supine in bed with my head on my pillow. I measure the pressure three times and record the third measurement.
Often my BP drops 20 points be the third measurement. This is because I relax and do my yogic breathing. Sharon didn't believe me at first. Now there is AMA style research to validate my assertion.
RESP@TATE is a company that is selling a biofeedback device to teach people how to slow down their breathing. By reducing respiration to less than 10 cycles per minute the body will relax and thus reduce the pressure on the vessels.
The study groups spent 15 minutes a day developing their deep breathing for eight weeks. RESPeRATE users with uncontrolled blood pressure experienced a decrease of BP by up to 36 points systolic ans 20 diastolic. The average reduction was 14/8 mmHg points.
I think that what has been discovered by western medicine has been known for centuries by yoga, qigong, tai chi and other eastern holistic people. Relax, you'll live longer.
Take a few deep abdominal breathes.