Hypertension, the silent killer — Why one blood pressure reading is not enough

High blood pressure is on the rise — both physiologically and statistically. Recognized as an essential vital sign measurement for human health, maintaining healthy and stable blood pressure levels is paramount for living a long and healthy life. High blood pressure (also known as hypertension) may seem harmless at first, but over time, this silent disease can lead to life-threatening complications like heart attacks, strokes, brain aneurysms, dementia, and kidney disease¹.

Despite its profound impact on our overall health, proper monitoring, diagnosis, and treatment for hypertension are severely lacking around the world. According to the World Health Organization (WHO), an estimated 1.28 billion adults are currently living with high blood pressure². Even more shockingly, it is estimated that, of those with the condition, 46% of people affected are unaware that they have the disease². This poor identification and diagnosis rate is, unfortunately, leading to increased severe health outcomes for people around the world. So why aren’t we doing more to manage this chronic disease?

Even with portable and automatic blood pressure monitors becoming more affordable and accessible, hypertension is still running rampant across the globe. From limited access to medical resources to poor technique and inaccurate readings, there is a multitude of reasons why an annual blood pressure reading is not sufficient to accurately diagnose high blood pressure.

So how does high blood pressure happen in the first place, and what can we do to tackle this silent killer before it has the opportunity to strike?

High blood pressure, explained

To better understand how high blood pressure occurs, we first need to understand how blood pressure is measured and reported. When we measure our blood pressure, we are actually recording two separate values. Most commonly, these values are recorded as one number above another (eg. 120/80 mmHg). Each of these numbers has there own unique physiological importance:

  • The top number (also known as the systolic blood pressure value) is a measure of the amount of pressure in the blood vessels during a heartbeat. Because the heart muscle has just contracted, there is an elevated amount of pressure in the large blood vessels, resulting in a larger perceived pressure in that moment¹.

  • The bottom number (known as the diastolic blood pressure value) is a measurement of the pressure in the blood vessels in between heartbeats. Because the blood vessels and muscles are at rest during this measurement, the amount of pressure recorded is lower than the systolic value.

Much like other chronic diseases, there are a variety of different risk factors that can result in someone developing hypertension.

While some causes of hypertension are non-preventable risk factors such as family history and advanced age, many of the common causes of this disease can be tackled by making healthier lifestyle choices. Some examples of hypertension risk factors that can be changed with healthier habits include³:

  • Increasing daily exercise levels

  • Reducing the amount of sodium (salt) consumed daily

  • Avoiding smoking tobacco products

  • Maintaining a healthy body weight

  • Limiting alcohol consumption

As our modern world continues to alter the day-to-day lifestyles of many people across the globe, more people are being diagnosed with hypertension every single year. With an estimated 700 million adults living with untreated high blood pressure, the number of people projected to experience serious negative health outcomes as a result of lack of treatment is truly astronomical⁵ ⁶.

How high is too high?

Throughout the day, our blood pressure levels will fluctuate and change depending on the amount of physical or emotional stress that we are currently experiencing. And while at times these fluctuations can be quite far off of someone’s baseline, as long as our blood pressure is able to return to normal values in a reasonable amount of time, our bodies are more than capable of handling these changes.

Things start to take a turn when the baseline values of both the systolic and diastolic blood pressure remain high for prolonged periods of time. Created to help identify and diagnose different stages of hypertension, a blood pressure chart is commonly used by health professionals to guide their decisions about treatments for high blood pressure.

The stages of a blood pressure chart include⁴:

Low (90/60 mmHg or less) — While some people like elite athletes do regularly have low blood pressure, numbers significantly lower than the baseline of 90/60 mmHg can be dangerous. It is advised that people falling in this range seek medical attention for monitoring by a health professional.

Normal (90-120/60-80 mmHg) — Considered to be the desirable range for human blood pressure, this range is typically the goal of most blood pressure therapies. At this range, there is a limited risk of serious injury or damage to the organs and blood vessels, which reduces the risk of developing a serious blood pressure-related condition.

Prehypertension (120-140/80-90 mmHg) — People in this category are at risk for developing chronic hypertension. If caught early enough, people living with prehypertension can make lifestyle changes to reduce their risk of being diagnosed with full-blown hypertension.

Hypertension Stage I (140-160/90-100 mmHg) — To be diagnosed with hypertension stage I, a patient’s blood pressure values must consistently fall within this range, even when at rest. It is common for people with stage I hypertension to be encouraged to make lifestyle changes while also being prescribed blood pressure controlling medications to prevent possible damage.

Hypertension Stage II (160/100 mmHg or more) — For patients with this range of blood pressure or higher, medical monitoring is highly encouraged. A combination of multiple blood pressure medications, lifestyle changes, and regular monitoring will be needed to reduce the risk of serious life-threatening complications.

Hypertension is on the rise, especially in developing countries

Hypertension has officially become a globalized problem. Unfortunately, this has been shown by the number of people living with hypertension massively increasing — from 650 million to 1.28 billion people over the past 30 years⁵.

Just like many other health conditions, the world’s developing countries seem to be hit the hardest with higher numbers of people living with the disease. While more developing countries like the Americas, Canada, and the United Kingdom report an average prevalence of hypertension of 30% of the population, developing countries in Asia and Africa have higher averages of 34% or more⁷.

While these percentages may seem small, the large populations of these developing countries mean that each increase in percent is equivalent to hundreds of thousands more people being affected by chronic high blood pressure.

There are large gaps in diagnosis and treatment

So how has a problem that is clearly integral to our overall health and wellness been able to increase to these astronomical numbers? Unfortunately, there seem to be multiple reasons why people fall through the cracks of the system and never receive the care they need (or even a diagnosis in the first place).

As a pretty straightforward diagnosis process involving routine monitoring of baseline blood pressure values, the current diagnosis rate is currently unacceptable. About 580 million people with hypertension (41% of women and 51% of men) are unaware of their condition because they have never been diagnosed, commonly due to limited access to regular health check-ups and basic medical resources⁵. And while efforts to increase the accessibility to basic healthcare around the world is helping to tackle this massive care gap, there are other reasons why high blood pressure is missed altogether by health professionals.

Health professionals don’t always measure blood pressure accurately

Getting an accurate blood pressure reading is not always the easiest task. Traditionally measured using a device called a sphygmometer, getting an accurate blood pressure reading is actually more of an art than a practical skill. Using an inflatable cuff placed around the arm, the practitioners place their stethoscope to the brachial artery in the vein as they begin to inflate the cuff. Once the cuff has been inflated to the point of occluding the artery, the air is slowly released as the practitioner listens for distinct noises (called Korotkoff sounds) as they monitor the pressure gauge on the sphygmometer⁸. While healthcare professionals are incredibly used to practising this skill, it is important to note that loud volumes of background noise and user error can easily lead to inaccurate blood pressure readings with this method.

Unfortunately, even the new modernised automatic blood pressure cuffs are not immune from significant deviations in their readings. Certain personal and environmental circumstances can result in dramatically different readings, which in turn can lead to missed diagnoses.

Some of the most common factors that can impact a blood pressure reading include⁹:

  • Minor inaccuracies (changes of a 2-8 mmHg) — Poor positioning of the patient’s arm, lack of back support, smoking tobacco prior to the reading, consuming vasoconstrictive substances like alcohol or caffeine before the reading.

  • Moderate inaccuracies (changes of 10-20 mmHg) — Taking the blood pressure reading too quickly after exercise, having a full bladder, and talking during the measurement.

  • Profound inaccuracies (changes of 20-40+ mmHg) — Using too small of a blood pressure cuff, taking the reading over clothing, and patient stress (also known as white coat syndrome).

Blood pressure readings are not enough

These inaccuracies, no matter how small, have a major impact on a person’s overall health. According to the Journal of Hypertension, a blood pressure reading that is only 5 mmHg inaccurate can lead to the incorrect hypertension stage diagnosis of up to 84 million people around the world¹⁰. On top of inaccurate readings preventing people from getting the correct diagnosis to receive the correct treatment they need, the “silent killer” nature of the disease means that many people do not experience any symptoms of the disease until it has progressed significantly.

So, it is clear that our previous standards of waiting for people to display symptoms of high blood pressure are not cutting it for actually getting people the diagnosis and treatment that they need to live happier and healthier lives. So what can we do to improve on our old ways?

Changing our lifestyle habits can help

Like we discussed earlier, there are many different risk factors that can play a role in a person developing high blood pressure. While some risk factors are not controllable, making conscious healthier decisions like increasing daily exercise and eating a balanced and nutritious diet are great ways to reduce the risk of developing this silent disease.

Looking for additional ways to help tackle the global problem of hypertension, the WHO released new guidelines designed to direct the future diagnosis and treatment of high blood pressure. Their recommendations include¹¹:

  1. Starting antihypertensive medications during the prehypertensive stage (blood pressures greater than 140/90). Starting antihypertensive medications at this earlier stage can help to slow the progression of the disease.

  2. When starting antihypertensive medications, it is advised that patients should also undergo screening for additional medical comorbidities, so the best possible treatment plan can be made for the patient’s specific needs.

  3. Patients should have a cardiac assessment done prior to or after the initiation of antihypertensive medication whenever possible.

  4. During the initiation of antihypertensive medication, it is advised that patients be put on combination therapy, where multiple antihypertensive medications are combined into a single pill. This has been shown to help with patient adherence to their treatment plan.

  5. Patients without any comorbidities should have a systolic blood pressure target of 140 mmHg or less. Patients with medical comorbidities should have a target systolic pressure of 130 mmHg or less.

  6. Patients should have a monthly follow-up appointment after a diagnosis of hypertension until they have reached their target ranges. Once they are within this range, they should still have follow-up appointments every 3-6 months with their care provider.

  7. Antihypertensive treatment can be made more accessible by allowing nonphysician professionals such as pharmacists and nurses to prescribe the medication, as long as they have the proper training, prescribing authority, know specific management protocols, and have physician oversight.

With these new guidelines being integrated into primary care around the world, the WHO is hopeful that future cases of hypertension can be stopped in their tracks before serious damage has been done. These changes paired with societal education and improved access to resources are the best options we currently have available for tackling this ever-growing problem.

  1. High Blood Pressure Symptoms and Causes | Center for Disease Control and Prevention

  2. Hypertension | World Health Organization

  3. High blood pressure (hypertension) | Mayo Clinic

  4. Understanding Blood Pressure Readings | Heart Attack and Stroke Symptoms

  5. More than 700 million people with untreated hypertension | World Health Organization

  6. Worldwide trends in hypertension prevalence and progress in treatment and control from 1990 to 2019: a pooled analysis of 1201 population-representative studies with 104 million participants (2021)

  7. The global epidemiology of hypertension (2020)

  8. 1.2.5 Blood pressure (BP) | OpenLearn Create

  9. Why Is My Blood Pressure Reading So High? 10 Factors that Affect BP Readings | American Diagnostic Corporation

  10. 4 big ways BP measurement goes wrong, and how to tackle them | American Medical Association

  11. Guidelines for the pharmacological treatment of hypertension in adults | World Health Organization

The author, Claire Bonneau, is a medical writer and certified trauma operating room nurse.

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