High blood pressure (hypertension) is one of the most common health problems worldwide. According to the World Health Organization, it affects more than 400 million people around the world and costs over $200 billion annually in medical care expenses.1 Hypertension causes many complications such as heart disease, stroke, kidney failure, blindness and other diseases.2
The main risk factors for developing high blood pressure are age, gender, race/ethnicity, physical activity level and family history.3 The incidence of hypertension increases with age; however, the increase is greater among women than men.4 Women have higher rates of hypertension than men due to hormonal changes during pregnancy and postpartum depression.5 High blood pressure may develop at any time but its development tends to accelerate between the ages of 40–60 years.6
Hypertension is the most common cause of cardiovascular disease (CVD).7 CVD includes heart attack, stroke, angina pectoris, peripheral artery disease (PAD), coronary artery bypass graft surgery (CABG), pulmonary embolism and other forms of vascular death.8
Cardiovascular diseases account for more than half of all deaths worldwide.9 Cardiovascular diseases account for approximately 70% of all cancer cases and 50% of all cancer mortality.10 Both high and low blood pressure are risk factors for CVD, but it is not exactly known what the threshold is for high blood pressure to become a risk.
High blood pressure is best treated by making lifestyle changes in addition to medication. There are many risk factors that interact; however, there are several practices that people can incorporate into their daily lives to improve their health and prevent future medical problems.
This article will discuss the relationship between high and low blood pressure with cardiovascular health, treatment and medical practices.
How to measure blood pressure
Blood pressure is symbolized by the letter “A” followed by two numbers, for example 120/80. The first number refers to the systolic pressure which represents the maximum pressure in the arteries during contraction of the heart (when the heart muscle is pushing the blood out). The second number refers to the diastolic pressure which is the minimum pressure in the arteries between heartbeats (when the heart is relaxed and refilling with blood).
Normal blood pressure is between 90/60 and 120/80.
Blood pressure monitoring at home is recommended for people who have been diagnosed with high blood pressure or are suspected to have high blood pressure. Home monitoring can be performed with a manual blood pressure device or a digital one. The devices used for measuring blood pressure are the same as those used in medical practices and laboratories, however, manual devices are less accurate and should only be considered as an estimate rather than an exact reading.
Blood pressure is typically measured in millimeters of mercury (mm Hg). Normal blood pressure is around 120/80. Prehypertension is around 120-139/80-89, Stage 1 hypertension is around 140-159/90-99, Stage 2 hypertension is around 160-179/100-110, and Stage 3 high blood pressure or hypertensive crisis is around 180mm Hg or higher and/or requiring immediate medical treatment.
Blood pressure guidelines
The American Heart Association makes the following recommendations for blood pressure:
In addition to the above, people diagnosed with cardiovascular disease, kidney disease, or diabetes should adhere to the following guidelines:
Blood pressure measurement devices
There are several classes of medical devices used in the measurement of blood pressure. These include manual auscultation devices, mechanical devices, and electronic devices. Mechanical devices include a rubber tube (called an “auscultatory gap” or “sphygmomanometer”), a large inflatable bag (for example the B-D device), or a device similar to a pressure cuff.
Each technique uses a stethoscope to auscultate (listen) over the pulse on the patient’s body and estimate the systolic and diastolic pressures.
Manual auscultation, also known as “orthostatic” or “Rudiccial” technique, is performed with the patient sitting normally and the practitioner auscultating over the brachial artery in the patient’s arm. This method is rarely used in modern medicine.
The “high pressure” or “oscillometric” technique involves inflating a cuff rapidly to pressures above 200 mmHg. This results in a relatively fast loss of blood flow to the extremity being measured. The cuff is then slowly released, listening for the first “swooshing” sound as blood flows back into the extremity, which should occur after less than 3 seconds.
This is the first of two “swooshes”, called the Korotkoff sounds. Once the second “swooshe” is heard (after 10-15 seconds), the pressure in the cuff is considered to be the diastolic blood pressure.
The “low pressure” or “bladder” technique involves inflating a cuff slowly to a pressure below 180 mmHg. When the first “swooshing” sound is heard, this is noted and then the cuff is slowly released until disappearance of the first swooshing sound. The cuff is then slowly released until disappearance of the second swooshing sound.
This is taken as the systolic blood pressure. A number of different auditory criteria, typically in the range of 130-160 mmHf, have been proposed as validation of the technique.
The “oscillometric” technique is considered more accurate than the “bladder” technique. The “bladder” technique is considered more accurate than the “orthostatic” technique.
This technology uses an inflatable cuff that is constantly inflated to a consistent pressure. The variation of the pressure applied is measured with an optical sensor, which can be used to measure blood pressure.
There are currently three systems that use this technology: Wrist-ABPM, NIBP2 and ACOSS.
Sources & references used in this article:
Effect of aerobic exercise on blood pressure: a meta-analysis of randomized, controlled trials by SP Whelton, A Chin, X Xin, J He – Annals of internal medicine, 2002 – acpjournals.org
Effect of exercise on blood pressure control in hypertensive patients by RH Fagard, VA Cornelissen – European Journal of …, 2007 – journals.sagepub.com
Arterial blood pressure response to heavy resistance exercise by JD MacDougall, D Tuxen, DG Sale… – Journal of applied …, 1985 – journals.physiology.org
Does exercise intensity affect blood pressure and heart rate in obese adolescents? A 6‐month multidisciplinary randomized intervention study by BQ Farah, RM Ritti‐Dias, P Balagopal, JO Hill… – Pediatric …, 2014 – Wiley Online Library
Effects of exercise, diet and weight loss on high blood pressure by SL Bacon, A Sherwood, A Hinderliter, JA Blumenthal – Sports Medicine, 2004 – Springer
How much exercise is required to reduce blood pressure in essential hypertensives: a dose–response study by K Ishikawa-Takata, T Ohta… – … journal of hypertension, 2003 – academic.oup.com