" A significant difference in the pressure recorded in the right and left arms can signal circulatory problems that may lead to stroke, peripheral artery disease, or other cardiovascular problems.
British researchers looked at the results of 20 studies in which blood pressure was measured in both arms. People with an arm-to-arm difference of 15 points or more were twice as likely to have peripheral artery disease-essentially cholesterol-clogged arteries in the arms, legs, or other non-heart parts of the body. The name may sound dismissive, but the disease isn't. Peripheral artery disease affects at least 12 million Americans, more than heart disease and stroke combined. It kills some, maims others, and makes life painful for countless more.
A blood pressure difference of 10 to 15 points or more between arms also boosted the chances of having a stroke or dying from cardiovascular disease. The results were published online in The Lancet.
In an editorial accompanying the article, Drs. Richard McManus and Jonathan Mant of the University of Oxford say that measuring blood pressure in both arms should be part of routine medical care.
Why does blood pressure differ between arms?
Different blood pressure readings in the right and left arms that vary by a few points aren't anything to worry about. It's actually quite normal. A difference of more than 10 points, though, could suggest trouble.
In younger people, side-to-side differences in blood pressure can occur when a muscle or something else compresses an artery supplying the arm, or by a structural problem that prevents smooth blood flow through an artery.
In older people, it's usually due to a blockage arising from atherosclerosis, the artery-clogging disease process at the root of most heart attacks, strokes, peripheral artery disease, and other cardiovascular conditions.
A less common cause of blood pressure that is different in each arm is an aortic dissection. This is a tear inside the wall of the aorta, the main pipeline of oxygenated blood from the heart to the body."
If your patient has 10 to 15 points different blood pressures between the right and left arm his PCP needs to be notified and he certainly has more significant problems than which numbers to use for giving him his blood pressure medication.