Blood Pressure on Left and Right Arms

Blood Pressure on Left and Right Arms




Different blood pressure in right and left arms
A significant difference in the pressure in the right and left arms can signal circulatory problems leading to peripheral artery disease, stroke or other cardiovascular problems.

People with an arm-to-arm difference of 15 points or more are twice as likely having peripheral artery disease – essentially cholesterol-clogged arteries in the arms, legs, or other non-heart parts of the body.

That same 15 point-difference in systolic readings also increased the risk of cerebrovascular disease by 60%.  Cerebrovascular disease is associated dementia 失智症/癡呆 and an increased risk of stroke.

Dementia     clickhere_green25
失智症/癡呆     clickhere_orange25


Blood pressure readings in the right and left arms that differ 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.

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.

Older people – usually due to a blockage from atherosclerosis, the artery-clogging disease process at the root of most heart attacks, strokes, peripheral artery disease, and other cardiovascular conditions.

Less common cause – aortic dissection 主動脈夾層動脈瘤.  This is a tear inside the wall of the aorta, the main pipeline of oxygenated blood from the heart to the body.


Aortic dissection 主動脈夾層動脈瘤     clickhere_orange25
主動脈夾層動脈瘤     clickhere_red25


Notes on taking readings:

  • Avoid caffeine, alcohol and nicotine 尼古丁 30 minutes before take reading.
  • Sit quietly for 15 minutes with back supported and feet on the floor.
  • When making the measurement, rest the arm with elbow at the level of heart.
  • Wrap the cuff over the bare skin of your upper arm.  Measure blood pressure according to the machine’s instructions.
  • Repeat the procedure in the other arm.

If the blood pressure readings are more than 10 or 15 points in difference, mention it to doctor at next doctor visit.


Report: (Posted March 05, 2014)
Researchers at Harvard-affiliated Massachusetts General Hospital and colleagues measured blood pressure—in both arms—in nearly 3,400 men and women age 40 or older with no signs of heart disease.

Small differences in blood pressure readings between the right and left arm are normal.  But large ones suggest the presence of artery-clogging plaque in the vessel that supplies blood to the arm with higher blood pressure.  Such plaque is a signal of peripheral artery disease (cholesterol-clogged arteries anywhere in the body other than the heart).  When peripheral artery disease is present, there’s a good chance the arteries in the heart and brain are also clogged, boosting the odds of having a heart attack or stroke ……..

Top Six Steps to Improve Cardiovascular Health – Suggestion

  • Don’t smoke
  • Be active
  • Aim for a healthy weight
  • Enliven your diet
  • Drink alcohol in moderation (if at all)
  • Ease stress

Full Detail  clickhere_orange25


Report: (Last updated: 27 March 2012 at 6am PST)
Varying Blood Pressure Readings In Each Arm Linked To Lower Survival Rates     clickhere_red25

A small difference in blood pressure between left and right arms is NOT considered a health concern.  But a difference of more than 20 millimeters of mercury (mm Hg) for systolic pressure or more than 10 mm Hg for diastolic pressure may be a sign of an underlying problem — such as narrowing of the main arteries to that arm.  If having a significant difference in blood pressure between arms, consult your doctor.

A large difference in blood pressure measurement between arms could be a signal of following health problems:

  1.     Blocked arteries in arms (peripheral artery disease)
  2.     Diabetes
  3.     Heart defects
  4.     Kidney disease


Daily Pattern of Blood Pressure
– normally lower at night while sleeping
– starts rising a few hours before wake up
– continues rising during the day with peak in the middle of afternoon.
– begins dropping again in late afternoon and evening

Potential causes of abnormal blood pressure pattern e.g. high blood pressure in the morning

  •     Kidney disease
  •     Poorly controlled high blood pressure
  •     Sleep apnea 睡眠窒息症/睡眠呼吸暂停
  •     Tumors of the adrenal gland

Sleep apnea    clickhere_blue25
睡眠窒息症/睡眠呼吸暂停     clickhere_orange25


Risk factors for developing abnormal blood pressure pattern include:

  •     Caffeine use
  •     Night-shift work
  •     Taking blood pressure medications that don’t last 24 hours
  •     Tobacco use
  •     Too much stress


Blood Pressure vs Weather Changes
Generally blood pressure is higher in the winter and lower in the summer.  Low temperature causes blood vessels to narrow resulting in more pressure being needed to force blood through the narrowed veins and arteries.

Additional to cold weather, blood pressure may also be influenced by abrupt change in weather patterns, e.g. a weather front or a storm.  Blood vessels may also react to abrupt changes in atmospheric pressure, humidity, cloud cover or wind in much the same way as its reaction to cold weather.  These weather-related variations in blood pressure are more common in eldery, age 65 and older.


The normal difference in bilateral indirect blood pressure recordings in normotensive individuals.
Published by : US National Library of Medicine National
Am J Emerg Med. 2001 Jan;19(1):43-5

Differences of more than 10 mm Hg in indirect bilateral blood pressure recordings are frequent in normotensive individuals and probably do not per se indicate any abnormal pathology.  In the right clinical situation, differences that are noted should probably be repeated and should be added to the total clinical picture when used to determine whether a pathologic condition is present…….

Full Detail    clickhere_orange25


CBS This Morning – Check blood pressure in both arms


Check blood pressure in both arms, sitting and standing


Different Blood Pressure in Both Arms Linked to Heart Disease



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