Understanding hypertension: causes, risks, and management

Hypertension, commonly known as high blood pressure, is a condition where the force of the blood against the artery walls is consistently too high. Often described as a "silent" condition, it can go unnoticed for years but significantly increases the risk of serious health problems if left untreated. It is one of the most common cardiovascular issues in the UK, affecting millions of adults. In this article, a consultant cardiologist furthers our understanding of hypertension’s causes, symptoms, and how it is treated.

What is hypertension?

Blood pressure is measured in millimetres of mercury (mmHg) and recorded as two numbers – systolic pressure (when the heart beats) over diastolic pressure (when the heart rests between beats). A reading consistently above 140/90 mmHg is considered high, though lower targets may apply to those with certain conditions such as diabetes or kidney disease.

Most people with hypertension do not experience any symptoms, which is why regular blood pressure checks are essential. When symptoms do occur, they may include:

• Headaches
• Blurred vision
• Shortness of breath
• Dizziness
• Nosebleeds

These signs usually appear only when blood pressure reaches dangerously high levels.

What causes hypertension?

There are two main types of hypertension:

• Primary (essential) hypertension – the most common form, which develops gradually over time without a specific identifiable cause. It is often related to ageing, genetics, and lifestyle factors.
• Secondary hypertension – caused by an underlying health condition, such as kidney disease, hormonal disorders, or certain medications (including the contraceptive pill and some painkillers).

Several factors increase the risk of developing hypertension, including:

• Obesity
• Lack of physical activity
• High salt intake
• Excessive alcohol consumption
• Smoking
• Stress

Hypertension is closely associated with other conditions such as type 2 diabetes, chronic kidney disease, and high cholesterol, forming part of a broader group of risk factors known as metabolic syndrome.

The dangers of untreated hypertension

When left uncontrolled, high blood pressure can lead to serious and sometimes life-threatening complications. Over time, the increased pressure damages blood vessels and vital organs, including the heart, brain, kidneys, and eyes. Key complications include:

• Heart attack and heart failure
• Stroke
• Chronic kidney disease
• Aneurysms
• Vascular dementia
• Vision loss

The risk of these outcomes can be significantly reduced with proper treatment and lifestyle changes. This is why early diagnosis and management are so important.

How is hypertension diagnosed?

Hypertension is diagnosed through blood pressure monitoring. One elevated reading is not enough to confirm the diagnosis; blood pressure must be raised on multiple occasions, or monitored over 24 hours using ambulatory blood pressure monitoring (ABPM).

As part of the assessment, a healthcare professional may also:

• Take a detailed medical and family history
• Check for organ damage with blood and urine tests
• Perform an electrocardiogram (ECG) or echocardiogram to assess heart health
• Assess cardiovascular risk using calculators that consider factors such as age, cholesterol, and smoking status

Routine checks are often carried out during GP visits, health checks, or during assessment for other conditions.

How is hypertension treated?

Treatment for hypertension involves a combination of lifestyle changes and medication. The approach depends on the severity of the condition and the presence of other health risks.

Lifestyle measures include:

• Reducing salt intake
• Eating a balanced diet rich in fruit, vegetables, and whole grains
• Regular physical activity
• Losing weight if overweight
• Limiting alcohol consumption
• Stopping smoking

When lifestyle changes alone are not enough, blood pressure-lowering medicines are prescribed. These may include:

• ACE inhibitors or ARBs
• Calcium channel blockers
• Diuretics
• Beta blockers

Treatment is often lifelong, and regular monitoring is essential to ensure blood pressure stays within a healthy range. The goal is to reduce the risk of complications, not just to reach a target number.