Hypertension: a silent threat to global health

Last updated:

13/03/25, 11:38

Published:

13/03/25, 08:00

Causes, symptoms, diagnosis and management

Introduction

Did you know that hypertension, also known as high blood pressure, is a leading cause of premature death, affecting 1.28 billion adults aged 30-79 worldwide? According to the World Health Organisation (WHO), two-thirds of these individuals live in low and middle-income countries. Despite its widespread prevalence, many people remain undiagnosed as most cases are asymptomatic, and individuals are unaware they have the condition.

Hypertension can lead to serious clinical manifestations such as heart disease. It can also cause eye retinopathy, causing vision problems and kidney damage, including proteinuria. It also contributes to vascular contributions like atherosclerosis, leading to stenosis and aneurysms. It also significantly raises the risk of stroke and heart failure (Figure 1). Addressing hypertension through early diagnosis, improved access to treatment and lifestyle changes is essential to reducing its global burden. This article aims to explore the causes, diagnosis and treatments.

What drives hypertension?

Hypertension is characterised by persistently elevated BP in the systemic arteries. Blood pressure is typically presented as a ratio: systolic BP, which measures the pressure on arterial walls during heart contraction, and diastolic BP, which reflects the pressure when the heart is at rest. Hypertension is diagnosed when the systolic blood pressure is 130 mmHg or higher and/or diastolic blood pressure exceeds 80 mmHg based on multiple readings taken over time (Figure 2).

In contrast, secondary hypertension occurs only in 5% of cases and is caused by an underlying condition, such as kidney disease, hormonal imbalances, or vascular problems. This form of hypertension is often reversible if the underlying cause is treated. Common causes of secondary hypertension include chronic kidney disease, polycystic kidney disease, hormone excess (such as aldosterone and cortisol), vascular issues like renovascular stenosis and certain medications. Drugs that can cause secondary hypertension include chronic use of non-steroidal inflammatory drugs (NSAIDs), antidepressants and oral contraceptives.

Hypertension, regardless of its cause, can be exacerbated by certain health behaviours, including excessive dietary salt, a sedentary lifestyle, heavy alcohol consumption, and diets low in essential nutrients, such as potassium. These factors contribute to the development and worsening of high blood pressure. However, blood pressure can be improved by reversing these behaviours, as well as following a diet rich in fruits and vegetables, which helps to mitigate the negative impact on blood pressure.

Spotting hypertension: how it is diagnosed

Hypertension is usually detected when blood pressure (BP) is measured during regular checkups. Since it often doesn’t show symptoms, all adults must check their BP regularly. The most common way to diagnose hypertension is by measuring BP several times in a doctor’s office.

To get an accurate reading, BP must be measured carefully. Since BP can vary throughout the day, multiple measurements are needed. Doctors have recently started using home BP monitoring (HBPM) and ambulatory BP monitoring (ABPM) to check BP outside of the office. ABPM records BP every 20-30 minutes over 24 hours, while HBPM lets patients measure BP at home. These methods help identify conditions like 'white coat hypertension' (high BP in the doctor’s office but normal at home) or 'masked hypertension' (normal BP at the doctor’s office but high at home).

When diagnosing hypertension, doctors also look for other health issues related to high BP, such as heart disease or kidney problems. If high BP is sudden or difficult to control, doctors may suspect secondary hypertension, which is caused by another condition, like kidney disease or hormonal imbalances. A thorough medical history is essential. This includes asking about past BP readings, medications, and lifestyle factors such as smoking and diet. Doctors also check for other risk factors like diabetes or high cholesterol, increasing heart disease risk.

A physical exam helps confirm the diagnosis of hypertension and checks for any damage to organs like the heart and kidneys. BP should be measured on both arms and if there's a significant difference in readings, further tests may be needed. If necessary, doctors may also check for conditions like atrial fibrillation or perform ultrasounds to look for heart or kidney problems. Blood tests can also help identify risk factors, confirm or rule out secondary hypertension, and assess overall heart health.

Managing hypertension, from lifestyle changes to medications

Studies show that weight loss can reduce systolic blood pressure by 5 to 20 mmHg, making it an effective strategy for managing hypertension. However, the exact "ideal" body weight or Body Mass Index (BMI) for controlling blood pressure is not clearly defined, but small weight reductions can make a difference. Reducing salt intake, staying active, and managing sleep apnoea also help. While smoking does not directly raise blood pressure, quitting reduces long-term heart risks. Overall, lifestyle changes alone can cut cardiovascular events by up to 15%.

Most national and international guidelines recommend the use of angiotensin-converting enzyme inhibitors (ACE inhibitors), angiotensin II receptor blockers (ARBs), calcium channel blockers (CCBs), and thiazide or thiazide-like diuretics as first-line pharmacological treatments for hypertension.

Conclusion

Hypertension is a prevalent and often silent condition with serious health consequences, including heart disease, stroke, and kidney failure. Its widespread impact on global health, particularly in low- and middle-income countries, underscores the importance of early diagnosis and proactive management. While lifestyle modifications are crucial in managing blood pressure, medications remain essential for many individuals. By raising awareness, promoting regular blood pressure checks, and ensuring access to both preventative and therapeutic measures, we can reduce the burden of hypertension and improve long-term health outcomes globally.

Written by Michelle Amoah

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Reminder to check your blood pressure (illustration)

Figure 2- systolic and diastolic readings determine stages of HT