What is the first thing that your healthcare practitioner does after you’ve settled yourself into the chair in their office? Inevitably, out comes the blood pressure cuff to assess your blood pressure. This is because this simple measurement can reveal a great deal about your health.
You may have heard about “risk factors” for disease. Risk factors are attributes or exposures that increase the likelihood of a person to develop a chronic disease or interfere in the management of existing conditions. High blood pressure is the biggest risk factor for heart disease. But there are others involved too. (1,2,3)
- Non-modifiable risk factors are those that we are not able to change like our age, ethnicity, family history and environmental risks such as air pollution.
- Behavioral risk factors are those that we have the most ability to modify. These include a poor diet (lacking in vegetables and fruits; high in processed foods), insufficient physical activity, smoking and drinking alcohol.
- Biomedical risk factors are conditions in the body that carry direct and specific risks for health. These risk factors include being overweight or obese, high lipid levels, kidney disease, prediabetes or diabetes and high blood pressure. Biomedical risk factors can often be prevented and sometimes reversed by improving behavioral risk factors.
High blood pressure (hypertension) is the number one risk factor for death globally, affecting more than 1 billion people, and it accounts for about half of all heart disease, strokes and heart failure worldwide. Severely high blood pressure (known as a hypertensive emergency) can be life-threatening. Severely low blood pressure reduces blood flow to body organs and can lead to life-threatening complications like shock. (4,5)
Hypertension is often called the “silent killer” because, though it is a powerful predictor of some of our leading causes of death, it rarely causes symptoms. Accordingly, routine blood pressure checks are crucial for keeping tabs on our heart health.
Normal blood pressure is below 140/90 mmHg. However, optimal blood pressure, a reading associated with the lowest risk of cardiovascular problems such as plaque build-up in arteries, stroke, or heart attack, is less than 120/80 mmHg. (6,17)
Note: Blood pressure is reported with two numbers. The first number is the systolic blood pressure which measures the pressure your blood creates against the artery walls as it beats. The second number is diastolic blood pressure which measures the pressure your blood creates against your artery walls when the heart is resting between beats. The measure for blood pressure is mmHg, a unit of pressure used to express the force exerted by blood against the walls of the arteries. (7)
How To Get the Most Accurate Results From a Blood Pressure Reading
Most people don’t plan ahead for a blood pressure check but, if you prepare yourself for the test, the accuracy of your reading can be improved by 10% or more. (8)
A recent study, published in JAMA in 2024, recruited 133 adults between 13 and 80 years of age. In a randomized crossover trial, participants had their blood pressure measured while their arms were in three different positions; supported on a desk (the standard recommended position), supported on their lap; or hanging by their side with no support. Each participant had their blood pressure recorded three times in each of the three positions. They then had a final blood pressure measurement with the arm again supported on a desk. (9)
Results showed that blood pressure measurements from an arm resting on the lap or hanging by the side were significantly higher than those obtained with the arm resting on a desk. (9)
- Average blood pressure of the participants was 126/74 when properly measured with the arm supported on a desk or table.
- Average blood pressure from an arm resting on the lap was 3.9 mmHg higher in systolic blood pressure and 4 mmHg higher in diastolic blood pressure. Average blood pressure of participants with the arm resting on the lap was 130/78.
- Average blood pressure from an arm hanging by the side was 6.5 mmHg higher in systolic blood pressure and 4.4 mmHg higher in diastolic blood pressure. Average blood pressure of participants with the arm hanging by the side was 133/78.
The conclusion of this study was that arm positions on the lap or hanging by the side can result in substantial overestimation of blood pressure readings with possible overdiagnosis of hypertension leading to unnecessary drug treatment. (9)
The reason for these differences in blood pressure is the relationship between the level of the heart and the level of the blood pressure cuff on the arm. For the most accurate result from a blood pressure reading, the middle of the blood pressure cuff around the arm should be level with the middle of the heart and the arm should be supported on a desk or table that achieves this positioning.
- When the cuff is lower on the arm than the level of the heart, blood pressure readings are misleadingly high.
- When the cuff is higher on the arm than the level of the heart, blood pressure readings are falsely low.
- Unsupported arm positions, such as on an arm hanging by the side, increase muscle tension which can raise both systolic and diastolic pressure.
Other tips for Optimal Blood Pressure Readings (8,10)
- In order to compare measurements, blood pressure should be taken at the same time of day. Blood pressure begins to rise a few hours before waking up, continues to rise during the morning, peaks at midday, and drops in the late afternoon and evening.
- Factors that temporarily increase blood pressure include caffeine, smoking and exercise. They should be avoided for at least half an hour before measuring blood pressure.
- Avoid checking blood pressure immediately after eating.
- Avoid checking blood pressure with a full bladder as that can raise blood pressure by 10 to 15 mmHg.
- When taking a blood pressure reading, sit on a chair that supports the back with feet flat on the floor and arm supported at the level of the heart. Crossed legs and dangling feet can erroneously raise blood pressure readings.Sit quietly for a few minutes before and during the blood pressure reading as movement and talking can increase blood pressure.
- The blood pressure cuff should not be leaky or too large or small for the person being tested.
- Do not place the blood pressure cuff over clothing. Measuring blood pressure with the cuff on top of a shirt sleeve can increase the reading enough to trigger a prescription for blood pressure medication.
- For the most accurate results, measure the blood pressure in both arms.
White Coat Syndrome (11,12)
White Coat Syndrome is a real condition that can cause problems when it comes time to measure blood pressure. White Coat Syndrome refers to blood pressure that is high only when measured in a healthcare setting. It happens when people become stressed and anxious in a doctor’s office, causing their blood pressure to rise above its normal level. This reaction can occur without the person being aware of it and even when they have a good relationship with their healthcare provider. White Coat Syndrome affects 15 to 30% of people and it is estimated that about 5% of those with White Coat Syndrome are misdiagnosed with hypertension every year, often leading to uncalled for treatment with medications and exposure to their possible adverse side effects.
Fortunately, there is a solution to White Coat Syndrome. Buy or borrow a good quality blood pressure machine or visit a pharmacy that offers free blood pressure tests. Take your blood pressure at the same time of day and using the same machine each time. Follow all the above tips for getting an accurate reading. Take readings at least twice each time and in both arms. Record your readings.
If you have at least three normal blood pressure readings under these conditions, report your results to your healthcare practitioners and they will take White Coat Syndrome into account when it comes to your blood pressure.
What To Do If Your Blood Pressure is High (13)
If you are diagnosed with hypertension there are many steps you can take to improve your situation. There is more than enough evidence supporting healthy lifestyle changes as an effective way to bring that pressure down. You don’t have to jump right into medications. Here are some suggestions.
- Eat healthfully. A diet that will lower blood pressure includes lots of plant-sourced foods (whole grains, fruits, vegetables, nuts and seeds) and low amounts, or even better, no amounts of animal-sourced foods, foods high in sugar and processed foods.
- Losing weight is one of the best ways to control your blood pressure. Even small changes will help. Studies show that weight loss can decrease blood pressure by 1 mmHg for every kilogram lost.
- Enjoy regular moderate to intense exercise daily. Try to include at least 30 minutes of exercise in every day. Aerobic exercise (jogging, brisk walking, cycling, dancing, swimming) has been shown to lower blood pressure by 5 to 8 mmHg. Strength training (lifting weights, push-ups) performed at least two days a week will also help.
- Reduce dietary salt (sodium) (14). Most people ingest far more sodium than is healthy. But the science on this is not yet clear. About a third of healthy people and about 60% of people with high blood pressure are salt sensitive and their blood pressure will increase 5 mmHg or more if they change from a low to a high-salt diet. On the other hand, about 10% of people have inverse salt sensitivity with their blood pressure rising when they eat less salt. This appears to be due to differences in genetics. Presently the general recommendation is to keep your salt intake below 2300 mg (about ½ teaspoonful) of salt daily. Even better is to try to achieve a lower daily salt intake of 1500 mg or less. Until this conundrum is solved, err on the side of keeping your salt intake low unless you see unexpected rises in blood pressure, in which case you will need to discuss this with your healthcare practitioner.
- Aim for little to no alcohol intake . Drinking alcohol can raise blood pressure significantly. Present recommendations call for less than one drink a day for women or two drinks a day for men but the ideal level of alcohol intake is none. Note: One drink is 12 ounces of beer; 5 ounces of wine; or 1.5 ounces of liquor.
- Stop Smoking (15). Smoking and vaping can raise blood pressure by 2 to 10 mmHg immediately after use with the spike in pressure lasting for about twenty minutes.
- Sleep Well. Hypertension is related to poor sleep. Try to get at least seven hours of sleep every night.
- Try to Avoid Stress. Stress can raise blood pressure. Make time for yourself in your busy life to relax and enjoy activities that are enjoyable for you.
SOURCES:
1 https://www.cdc.gov/heart-disease/risk-factors/index.html
2 https://www.who.int/news-room/fact-sheets/detail/cardiovascular-diseases-(cvds)
3 https://www.aihw.gov.au/reports-data/behaviours-risk-factors/risk-factors/overview
4 https://my.clevelandclinic.org/health/diagnostics/17649-blood-pressure
5 https://world-heart-federation.org/what-we-do/hypertension/
6 https://cwhhc.ottawaheart.ca/education/risk-factors/blood-pressure
7 https://www.heart.org/en/health-topics/high-blood-pressure/understanding-blood-pressure-readings
8 https://www.health.harvard.edu/heart-health/tips-to-measure-your-blood-pressure-correctly
9 Liu, H., Zhao, D., Sabit, A., et al. Arm Position and Blood Pressure Readings: The ARMS Crossover Randomized Clinical Trial. JAMA Intern Med. 2024;184(12):1436–1442. Doi:10.1001/jamainternmed.2024.5213
11 https://my.clevelandclinic.org/health/diseases/23989-white-coat-syndrome
12 https://www.health.harvard.edu/staying-healthy/white-coat-hypertension-a-cause-for-concern
14 https://www.health.harvard.edu/heart-health/dietary-salt-and-blood-pressure-a-complex-connection
15 Jason, J… Rose, M.B.A., Krishnan-Sarin, S., Exil, V.J., Hamburg, N.M., Fetterman, J.L. Cardiopulmonary Impact of Electronic Cigarettes and Vaping Products: A Scientific Statement From the American Heart Association. Circulation.2023;148:703–728. Doi: 10.1161/CIR.0000000000001160
16 https://www.mayoclinic.org/diseases-conditions/high-blood-pressure/expert-answers/blood-pressure/faq-20058115
17 https://newsinhealth.nih.gov/2016/01/blood-pressure-matters
.
Promoting a healthy adventurous lifestyle powered by plants and the strength of scientific evidence.
My name is Debra Harley (BScPhm) and I welcome you to my retirement project, this website. Over the course of a life many lessons are learned, altering deeply-rooted ideas and creating new passions.
