Earlier today i took a blood pressure reading on my left arm. The numbers were in the "hey, not bad" range. (137/68) i then switched to the right arm and got numbers that were in the "uh oh" range. (152/80) Now, i know you're supposed to take the highest of the readings as your true number, but there's a possible catch here, and i want to know everyone's thoughts on this. My right triceps is visibly swollen from an injection on the previous day. Would that swelling of the arm skew the reading or do i need new batteries in this thing?