Why Do They Draw Blood From Your Left Arm

The next time you have your blood pressure checked, don't be surprised if your doctor, nurse, or other health-care provider measures it twice—once in each arm. 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.

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.

Try this at home

At your next doctor's visit, ask to have your blood pressure checked in both arms. If there's a difference greater than 10 point, another test called the ankle-brachial index might be in order to check for peripheral artery disease. It might also be a good time to get serious about taking care of your heart and arteries.

If you take your blood pressure at home, you can do it yourself. There are many good reasons to check your blood pressure at home. The result might be closer to your usual blood pressure than the result in a doctor's office, and you might do a better job of measuring your blood pressure.

That's why theHarvard Heart Letter urges people to check their own. All it takes is a home blood pressure monitor, a few simple instructions, and a few minutes. You can see a video here, or read more about home monitoring from theHeart Letter.

Here are a few tips to help you start monitoring your blood pressure at home:

• Avoid caffeine, alcohol, and nicotine during the 30 minutes before you take your reading.
• Sit quietly for a few minutes with your back supported and your feet on the floor.
• When making the measurement, rest your arm so your elbow is at the level of your heart.
• Wrap the cuff over the bare skin of your upper arm. Measure your blood pressure according to the machine's instructions. Leave the deflated cuff in place, wait a minute, then take a second reading. If the readings are close, average them. If not, take a third reading and average the three.
• Repeat the procedure in the other arm.

If the different blood pressure readings in your arms are off by more than 10 or 15 points, mention this at your next doctor visit and ask your doctor or nurse to check both arms.

Image: Amorphis/Getty Images

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Hi everyone. For 3 months I suffered with lots of dizziness and nausea. Most of the medications from the Doctor did not work, I then went onto Sturgenon which helped a bit but I still get dizzy turns especially in bed, getting up and lying down. My ENT Doc said it wasn't to do with my ears and after taking my pulse (it has an abnormal rythme) said it was most likely to be my heart. Three years agao I had a metal plate put in my neck at C3/C4, my own GP thought that a trapped nerve could be the problem. Recently I have been getting blue nails so started to check BLOOD PRESSURE IN BOTH ARMS. There is continually a lower pressure in my left arm of between 27mmHg and 48mmHg. I am due to have a DOPPLER test soon, but in the meanwhile I worry about having a stroke or heart attack. To make things worse I am 65 years old, have Chronic Kidney Disease and am due to have Chemotherapy in a few months for Chronic Lymphocitic Leukemia (Had CLL for 11 years) as the white blood count is 116. Is all this inter-related, I try to keep fit and healthy but amm now beginning to get paranoid about my health. Any comments welcome.

Craig Taylor

March 12, 2012

hello, anyone good with medical instrument here? I need some suggestion with blood pressure device. problem is that i don't know what type of blood pressure gauge is best. any suggestion? please do share your comments regarding that link. thanks.

Any blood Pressure machine from your pharmacy will be OK. Don't be fooled by all the different ones advertised on the internet, they are really basically, all the same.

OK…so I've had big disparities between the left and right readings (the right almost always quite a bit lower) and my doctor, to rule out anything, sent me for a doppler test in my arms…result…PERFECTLY normal! She thought my concern was needless to begin with and her take on it is that the disparity is normal, I am in NO danger, and I should forget about all this. Whom to believe???? There is as much as a 20 point difference in my arms at times for both systolic AND diastolic. I'm baffled but I have NO pain in my arms, no one ever had any suspicion of any blockage though I'm 65 years old, I take my BP medication, and my decision on this is to forget about it and just be glad I've gotten to be as old as I am already! The world is about to blow up anyway so why worry???? It's too easy to become a hypochondriac. In the end I think the medical profession is less knowledgeable than they pretend to be. Especially when it comes to cardiovascular things. Look at the insanity going on now about statins…take them, don't take them…I decided years ago to ignore the doctor's suggestions about them. 20 years from now they'll probably be held in as much disrepute as HRT and cox-2 inhibitors are now. For a person with no cardiovascular disease, it seems crazy to try to lower cholesterol numbers radically. Less is not always more. And it is possible for many of us to achieve very respectable numbers with diet, OMEGA 3 supplements, and exercise. Nutritional professionals do not agree that a total cholesterol of 150 or even less is desirable. Yet the hucksters selling these drugs would put them in the drinking water if they could make enough money doing so. Human life is not a disease…yet we seem to treat ourselves as though it is. So…sorry to go on and on with what started out as a simple remark about blood pressure…but maybe it's not GOOD to have doctors telling us that we are about to die of every little thing…a headline like "could signal trouble" will doubtlessly often leave us in the dark. My doctor shrugged her shoulders and told me to forget about it…maybe that's a good suggestion!!!!

Shouldn't this article include which side demonstrates the periperal issue? Is it the side with the higher reading or the side with the lower reading?

LowerHigher

March 1, 2012

Exactly Edman. I have a lower reading in the left arm (118/70) and a higher reading in the right (132/82). In all accounts and on many readings, I'm averaging 18 higher systolic which, according to all info I've read, makes me "more likely" to have periperal artery disease. But I cannot understand why there's no explanation as to which arm is the problem arm. Common sense says if there's blockage, the lower reading arm is the problem. But that also suggests low blood pressure which would mean the reading would evade most doctors checking for heart disease! Even above under "What is the Cause" it doesn't suggest which arm is the culprit.

This is very crucial for people to know. My doctor actually advised me of this, and I was a bit taken back to know this could be a problem.

Good post.

I've asked all of my doctors this question and none of them will answer it. Why is it blood pressure can vary significantly within a few minutes or less using the same blood pressure monitor?

Also, why is it that different monitors record different pressures even if taken within a moment of each other? I have had this occur in my doctor's office and it makes me wonder about how accurate any blood pressure monitor really is.

The reason the blood pressures are differnt is because the blood vessals have not fully recovered from the first blood pressure. You need at least 5 minutes (or more) for the blood flow and pressure to bounce back to normal. Hope that helps.

Our body has a definite blood perssure. A drop in the said perssure is a condition termed as hypotension, more popularly low blood perssure. In such a condition, the heart forces the blood out of the arteries with much less strength than it should. Low blood perssure is an outcome of weakened and devitalized system. Some of the main causes of low blood perssure are faulty nutrition or malnutrition, emotional instability, loss of blood and slow internal bleeding. Lethargy, weakness, fatigue and dizziness are the most common symptoms of low blood perssure. A person might even faint, if the arterial perssure gets extremely low. Low blood perssure can, however, be treated naturally, using some home remedies. Read on to know how to cure low blood perssure, at home.Home Remedy For Low Blood Pressure * The best and the most effective home remedy for treating low blood perssure would be to consume lots of water. This is because dehydration reduces blood volume and leads to a drop in the blood perssure. * Beetroot juice is beneficial for those suffering from low blood perssure. So, have a cup of raw beetroot juice two times a day. * Prepare a cup of strong black coffee and consume this whenever you feel that your blood perssure is dipping. * Put 15-20 gm of Indian Spikenard in 250 ml water and boil it. Now, remove from heat and let it cool down. Have this infusion thrice a day. You can also have 30-40 grains of Indian Spikenard, along with some camphor and cinnamon. * Fill your bathtub with lukewarm water and add one kg of Epsom salt to it. Immerse yourself in the bath for 20 minutes, before going to bed. Take caution not to expose the body to a cold area after this. * In a bowl of water, soak 7 almonds and keep them overnight. Peel them and prepare a paste. Add this paste to lukewarm milk and drink it. * Take a bowl of water and soak 30 raisins in it, overnight. Chew them one by one, on an empty stomach, in the morning and have water. * Holy basil works effectively in curing low blood perssure. Take about 15 holy basil leaves and crush them. Filter the mixture with the help of a muslin cloth. Have this filtered mixture, along with a tsp of honey, on an empty stomach. * Include salt, asafoetida and fruits in your diet. All these are beneficial in restoring the blood perssure level. * Foods rich in proteins, vitamin C and vitamin B are effective in treating low blood perssure. * Exercises, light walking, swimming and cycling are beneficial in regulating the blood perssure level. Was this answer helpful?

Claudia Juárez

February 1, 2012

As blood pressure significant differences in hands temperature can be a signal of circulatory problems. This can be measured with temperature sensors used in biofeedback procedure. With this technique, you can aware of imbalance, but also you can improve it.

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Why Do They Draw Blood From Your Left Arm

Source: https://www.health.harvard.edu/blog/different-blood-pressure-in-right-and-left-arms-could-signal-trouble-201202014174

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