lower on one side than the other

corn farmer,

Thanks for your question.

First, I want you to know that I never trust a home blood pressure machine until I ask the patient to bring the machine to my office and I watch him/her take their own pressure.  I observe their technique and placement of the cuff.  Then I always take their pressure with my equipment and compare the two readings.  If they are the same, then I know I can trust the reading obtained at home.  So be sure your readings and technique are accurate.

Now, back to the question.  It is not unusual to have some minor differences between each arm.  If there is more than 10 - 15 mm difference, this needs to be addressed by your physician.  If a patient is elderly, I would not be as concerned, as atherosclerosis with stiffening of the arteries can easily account for these changes.  In a younger person, there are a few things to think about, such as blockages or narrowing of major arteries in the chest, shoulder and arm (sometimes congenital).  Again, your doctor knows you and your history and is the best person to decide whether the difference in pressure from one side to other is something to be concerned about.

I hope this has been helpful.  Best wishes.

Martin Cane, M.D.