Standing Blood Pressure Reading

[coldhoist]

What is the correct way to take the standing blood pressure reading? Should the arm be level with the heart or should the arm be hanging down to the side?
I asked my doctor's nurse this question and she said the arm should be level with the heart. One of the nurses at my dialysis center was trying to tell a patient that she was taught that the arm should be level with the heart and the patient did not believe her.. My technician insists that the arm should be down the side.  The Mayo clinic says the arm should level with heart as having the arm hang down the side can increase the blood pressure reading by 10-15 points.
So, what is the correct to take a blood pressure reading? I am confused.

[rcjordan]

We've always done level with the heart.