What is High Blood Pressure?
High blood pressure, known medically as hypertension, is a condition where the force of the blood against your artery walls is consistently too high. In the UK, it is a leading risk factor for cardiovascular disease, yet many people remain unaware they have it. Because the heart must work harder to pump blood when pressure is elevated, it can lead to damage over time. This article explains the clinical standards used by the NHS and helps you understand what your readings mean for your wellbeing.
What We’ll Discuss in This Article
- The clinical definition of hypertension and how it is measured.
- Why high blood pressure is often described as a ‘silent’ condition.
- The specific readings that indicate a health risk.
- Common lifestyle factors and medical causes for the condition.
- Physical and environmental triggers that cause temporary spikes.
- The distinction between primary and secondary hypertension.
- Key safety guidance for those experiencing severe symptoms.
Understanding Blood Pressure and Its Impact on the Body
High blood pressure is a condition where the heart pumps blood with excessive force against the artery walls. In the UK, it is defined as a consistent reading of 140/90 mmHg or higher in a clinic, or 135/85 mmHg during home monitoring. Over time, this extra pressure can weaken blood vessels and increase the risk of serious health issues like heart disease or stroke.
Blood pressure is recorded using two numbers:
- Systolic pressure: The pressure when your heart beats and pushes blood out.
- Diastolic pressure: The pressure when your heart rests between beats.
A healthy reading is usually considered to be between 90/60mmHg and 120/80mmHg. If your numbers are consistently high, the arteries may lose their elasticity and become narrow, making it harder for oxygen rich blood to reach your organs.
What are the Symptoms of High Blood Pressure?
Hypertension rarely causes noticeable symptoms, which is why it is often called a ‘silent’ condition. Most people feel completely well even if their blood pressure is high. Symptoms typically only appear if the pressure reaches a dangerously high level very quickly. Regular testing is the only reliable way to find out if your blood pressure is within a healthy range.
If symptoms do occur due to an extreme rise in pressure, they might include:
- Severe or persistent headaches.
- Blurred vision or changes in sight.
- Unexplained nosebleeds.
- Shortness of breath.
- Chest discomfort.
The NHS recommends that all adults over the age of 40 have their blood pressure checked at least every five years to catch any changes early.
How is Blood Pressure Diagnosed?
A diagnosis is not usually made from a single reading because blood pressure changes throughout the day. To confirm hypertension, UK clinicians often use Ambulatory Blood Pressure Monitoring where a cuff is worn for 24 hours. Alternatively, you may be asked to monitor your blood pressure at home for a week to get an average reading that reflects your daily life.
This process helps to rule out the ‘white coat’ effect, where a person’s blood pressure rises simply because they are in a medical environment or feeling anxious about the test. By looking at an average of several readings, healthcare professionals can make a more accurate assessment of your cardiovascular health.
Causes of High Blood Pressure
For most people, there is no single clear cause for high blood pressure. This is referred to as primary hypertension. It usually develops over many years because of a combination of genetics and lifestyle factors. Common contributors include a diet high in salt, being overweight, a lack of regular physical activity, and drinking too much alcohol.
Key risk factors identified by NICE include:
- Age: Risk increases as you get older and blood vessels become stiffer.
- Ethnicity: People of Black African or Black Caribbean descent are statistically at a higher risk.
- Salt intake: Consuming more than 6g of salt per day encourages the body to retain fluid.
- Family history: Having a close relative with hypertension increases your own likelihood of developing it.
Common Triggers for Blood Pressure Spikes
Temporary spikes in blood pressure can be triggered by immediate external factors. These include caffeine consumption, smoking, acute stress, or even very cold weather. While these spikes are usually short lived, they can be a concern if they happen frequently or if they occur during a medical test, leading to a misleadingly high result.
Specific triggers include:
- Caffeine: Energy drinks or strong coffee can cause a sharp, temporary rise.
- Emotional stress: The release of hormones like adrenaline causes the heart to beat faster.
- Smoking: Nicotine causes immediate narrowing of the blood vessels.
- Certain medications: Some over the counter cold and flu remedies contain ingredients that can raise pressure.
Primary vs. Secondary Hypertension
Hypertension is divided into two categories based on why it happens. Primary hypertension is the most common and develops slowly due to lifestyle and age. Secondary hypertension is caused by an underlying health problem, such as kidney disease or a hormonal imbalance. It often appears more suddenly and can cause higher readings than the primary form.
Comparison of types:
- Prevalence: Primary accounts for about 95 percent of cases while secondary is less common.
- Onset: Primary develops gradually; secondary often appears abruptly.
- Causes: Primary is linked to weight and diet; secondary is linked to specific conditions like sleep apnoea or thyroid problems.
- Treatment: Primary is managed with lifestyle and standard medication; secondary requires treating the underlying medical issue.
Conclusion
High blood pressure is a common condition that requires consistent management to prevent long term health complications. Because it often lacks symptoms, regular monitoring is the best way to stay informed about your heart health. Making small changes to your diet and activity levels can have a significant positive impact on your readings.
If you experience severe, sudden, or worsening symptoms, call 999 immediately.
What is a ‘normal’ blood pressure reading?
A normal reading for most adults is generally considered to be between 90/60mmHg and 120/80mmHg.
How does salt affect blood pressure?
Salt makes your body hold onto water, which increases the volume of blood in your system and raises the pressure.
Can stress cause hypertension?
While short term stress causes spikes, chronic stress can lead to long term high blood pressure by affecting your lifestyle habits.
What is the ‘white coat’ effect?
This is a temporary rise in blood pressure caused by the anxiety of being in a hospital or clinic setting.
Is high blood pressure hereditary?
Yes, your genetics play a role, so you are more likely to have high blood pressure if your parents do.
Can I lower my blood pressure without tablets?
Many people can lower their readings by losing weight, exercising more, and reducing their salt and alcohol intake.
Authority Snapshot
This article has been reviewed by Dr. Stefan Petrov, a UK trained physician with an MBBS and postgraduate certifications including Basic Life Support and Advanced Cardiac Life Support. Dr. Petrov has hands on experience in general medicine, surgery, and emergency care within hospital wards and intensive care units. This guide provides evidence-based information following NHS and NICE protocols to help you understand hypertension safely.
