Left arm vs. right arm blood pressure question

The plumbing from the heart to the left arm is more direct than to the right arm, so in order to get truer numbers, the left arm is preferred. In instances where the left arm is injured, or a reading is otherwise impossible, then the right arm is used. The readings are normally a few points lower, but the difference is not very significant.

My understanding is that immediately after, it would be quite high. (Raised by trying to pump a larger blood volume through the same piping.) And, I haven't played around with that.

Regarding your second question, my instinct says it's unlikely that you could do that. (I can't believe I even tried to give a serious response.)

Your systolic(upper number) BP will be higher on your left arm because of its proximity to the pumping ventricle of the heart. For this reason it is also more representative of the pressure created by the heart as it pumps which is why the left side is preferred.

The diastolic (lower number) BP is the remaining/minimum pressure in the blood vessels between beats. This number should be similar between the right and left arms becasue it is not exactly a direct result of the pumping of the heart.

The diastolic BP is more important because it indicates the pressure in the arteries which the heart must pump against to get blood out. If it's high, the heart is under more stress to pump blood out.

As an athlete, your systolic pressure is likely higher because your heart is larger and pumps more blood more foreably with each beat.

Why do they check the right arm to verify a reading?...because if you were to check your pressure again in your left arm, it would be a little different because you just applied a large constrictive force by checking it the first time. It's not a matter of left versus right.

Immediately after a hard effort, your systolic would be well over 200 and your diastolic would be only slightly elevated. This, of course, can vary a good bit due primarily to your heart rate. If your HR is really high, there just isn't enough time for your heart to fill with blood returning in the veins so the volume you're pumping out is small and the systolic pressure is not going to be high.

Strictly an educated guess...the diastolic pressure in your erect penis would be through the roof and your systolic would be high enough to overcome the diastolic, but not nearly as high relatively. If your systolic (the upper number...a result of the pumping of the heart) were really high, your penis would be popping up and down like a party favor with each heart beat.

hope this helps.

Generally I would agree with this post however I differ on:

Part of the reason the left arm is preferred is because it is closer to the heart; also, it is part of standardization. If you are wanting to see changes in your BP over time, then you want to measure it the same way (same time of day as well) each time.

One reason to look at BP in both arms is to look for large differences that might be indicative of some sort of circulatory issue.

Within a minute or so, the restrictive forces in re-taking a BP would be gone and you would could get a similar reading.

The real concern with most BP units of the manual type are calibration and operator error. The calibration can be way, way off and it is really impossible to tell without checking it against some standard.

I disagree that at rest a trained person's systolic pressure would be higher. This really goes against a reason for people to exercise (that is to lower BP). In fact, a trained person might have a lower systolic because the blood vessels are not going to be as restrictive to the flow of the blood.

I am not sure how many BP measures 123 has done, but systolic pressure during exercise can be very, very high. At a high HR, the venous return is still very high. While the LV might not be filling completely the rate is such that the time between beats is very small so the pressure remains high and near constant. Diastolic pressure will decrease or stay the same (rarely rise) because of vasodilation from other factors at work on the smooth muscle of the vessels.

Some people do look more closely at diastolic pressure in terms of CV disease for some of the reason you note. Also a t rest (which is where we spend 22+ hours of the day) your diastolic pressure is the pressure exerted on the artery walls 2/3 of the time. In some ways that is more strain than the occasional pulse of high pressure blood coming by.

As for the penis issue, blood flow is restricted to the penis most of the time. Not really sure that this has to do with the issue at hand other than some BP meds create erectile dysfunction and it seems like many of the posters here think with their dicks.

Agreed, my statement about the trained person's SBP was misleading. I was offering an explanation for why veryyy's SBP may be a little above normal. I was also making the asssumption that this is a highly trained and otherwise healthy, young individual, not just a regular exerciser.

It is possible that DBP may drop a little while the body adjusts to exercise, it must ultimately be maintained or somewhat elevated in the areas of the body which are not exercising (ie. the arms of a runner) so that blood is directed towards the active muscles. The sympathetic response to exercise causes a general vasoconstriction throughout the body while local factors in the active muscles cause vasodilation, promoting blood flow from inactive to active tissues.

If left is much lower than right there may be an anatomical problem, like coarctation of the aorta. Worth comparing. (At least once in your life, anyway!)

can u tell me why my left arm always registers as abnormally low blood pressure but right arm is ok 110/70, i am having a few problems with aches n pains in left shoulder and arm and wondering if that is why the abnormal reading

Issy,

Let me preface this by saying that I have no formal medical training, but a fairly good "layman's" knowledge of BP.

The likely cause of your unusually low BP in your left arm is some type of obstruction between it and the heart. It may be something minor and congenital, like a convolution in the artery. It could also be the result of an injury or surgery - a scarred artery may be partially constricted. It could also be plaque in the artery - if this is the case, you may be at risk of stroke or heart attack. One clue would be your personal history. Have you been this way all your life? Has it changed? Was there anything that might have caused this change?

Wayne

I couldn't add much to Wayne's note, issy. You can get imaged for these things that can narrow your aorta. Ask your doctor. I'd *guess* if you've been stable for a long time like this it's probably nothing to worry about.

I understand the logic of using the left upper arm to measure blood pressure however I'm wondering about false readings for those of us Leftys playing a lot of tennis. I recently bought a good BP tester after my apparently healthy and much younger friend practicing for a tri-althelon dropped dead and another friend who normally plays tennis for hour 3 hours every week and runs, dropped dead at the court. I'm wondering if the tension in the arm would give a false reading. Also could the initial tightening of the cuff change the reading? Sometimes it fills to 184,195, anoter 205, right arm it pumped to only 165. Left arm relaxed after 3 hours after tennis is usually 135/85 or often with a cold 139/85. Yesterday it shot up to 147/90 as the wife was complaining about taking so many readings between 7:30PM and 9:00PM. The last 2 readings were 132/87 and 134/81 which is believable. Can the tight BP's armband cause a blockage to move and then the reading drops? Right Arm was 139/87 then at 9PM dropped to 130/80. I have no health problems. Can food Spaghetti sause at supper change the BP a couple hours later? BP unit fro mPharmacy is Omron Series 10 with cuff BP785. Should I test the BP in the middle of a run or tennis match? How much should the BP shoot up without killing me?

Thank you for giving honest information. Minus the stupid penis people. My bp is scary 147/97 left 117/77 right. This info is making me call my doc tomorrow. I just happened to take it because i was dizzy. Thanks for sharing.

Did you found out why is it big of a difference?

All you could ever want to know here:

https://www.ahajournals.org/doi/full/10.1161/HYP.0000000000000087