High blood pressure

What is high blood pressure or hypertension?

High blood pressure affects more than 1 billion people worldwide and is the most common cause of cardiovascular disease. It happens when blood is pushed against the artery walls at a consistently high force during each heartbeat. The condition and size of the artery walls can also impact blood pressure.

Pressure rises when blood is pumped out of the heart and lowers when the heart is at rest. Your blood pressure increases and decreases during the day. This is normal and blood pressure only becomes an issue if it remains consistently high. Our cardiovascular specialists can help you understand your risk and potential treatment or management options, if needed. 

How is blood pressure measured?

Blood pressure is typically measured using a special monitor. This includes a cuff that you fit around your upper arm and is attached to a machine. The cuff tightens around your arm and detects your measurements which are then shown in the digital display. 

The measurements are displayed as two numbers that indicate millimetres of mercury (also shown as mmHg) in the following example format: 

120/80 (meaning 120 over 80)

The top number (in this case 120) is the measurement of systolic pressure which is the pressure created when the heart pushes blood around the body. The bottom number (80) is the diastolic pressure, which is the pressure created when the heart is at rest between beats.

What is a normal blood pressure reading? 

Normal blood pressure readings are typically between 90/60 and 120/80. If you have consistent blood pressure readings of 135/85 or above, you might be experiencing hypertension. 

People with conditions such as diabetes, heart failure or coronary artery disease should have a lower reading, one that's below 130/80, due to the increased risk of serious complications. 

We’ll explain your blood pressure reading in detail to help you understand what it means for your health. 

High blood pressure vs low blood pressure

Low blood pressure (hypotension) is when the measurement is 89/59mmHg or below. While measurements can sometimes be below the normal range, very low blood pressure can, in some cases, be a sign of an underlying condition, infection or dehydration. It can also be caused by certain medications.

What causes elevated blood pressure? 

It’s not clear what causes high blood pressure. The majority of people with hypertension display no symptoms and have what is called primary hypertension. This means that there’s no underlying cause of high blood pressure (such as an adrenal tumour or some form of kidney disease).

Secondary hypertension is experienced by a small percentage of people which means there are one or more underlying factors involved. These can include health conditions, certain medications or excessive alcohol usage. 

Risk factors for hypertension

Multiple factors can increase your chances of developing primary high blood pressure, many of which are related to lifestyle:

• Age – it's more common in people aged 60 or over
• Being overweight 
• Lack of physical activity
• Too much salt or high fat in your diet
• Drinking excessive amounts of alcohol 
• Smoking
• High stress
• Family history of hypertension 
• African Caribbean or South Asian background 

We can help you understand more about your personal risk. 

What are the complications of hypertension?

Untreated, hypertension can lead to serious cardiac disease and even cause:

• Heart attack
• Stroke 
• Aneurysm 
• Blood clots

These cardiac conditions can be severe and, in some cases, can have life-threatening consequences. This makes regular check-ups and effective treatment and management key, which we can provide personalised help with.  

High blood pressure diagnosis 

Hypertension is often diagnosed during a routine health check. It's recommended that everyone over the age of 40 has their blood pressure checked at least every five years. This can be done for free at your GP surgery, clinics or some pharmacies. 

If you have signs of consistently high blood pressure you might be referred for extra tests to monitor the measurements over a longer period. If needed, we’ll discuss the most relevant options with you so you know what to expect. 

Blood pressure reading

This is a simple test that gives you a reading of your blood pressure at that specific time. You'll be asked to sit down on a chair with back support and have your legs uncrossed before your blood pressure is taken.

Your consultant will usually use an automatic digital device with a sensor to measure your blood pressure (oscillatory device). You might need to roll up your sleeve or remove any long-sleeved clothing so they can access your upper arm. 

A cuff is then attached to the upper arm and inflated above an individual's systolic pressure. Vibrations through the arteries are detected by the device and converted into a measurement. The result will be available immediately on the digital display. 

If your blood pressure reading has been recorded as high during a GP or clinic appointment, you might be asked to return to repeat the test. If this still shows an elevated measurement, you might be asked to use an at-home blood pressure monitor and record the measurements twice a day over a period.

Ambulatory blood pressure monitor 

An ambulatory blood pressure monitor automatically records blood pressure measurements multiple times a day over 24 hours. 

You'll need to wear a cuff on your upper arm and a box around your waist. You will usually feel the cuff inflate every half an hour throughout the day and every hour at night. It's fine to continue with your usual activities during this time, although it's recommended not to drive other than to and from the appointment. 

You will usually return the device to the clinic after you've completed the test, where your results will be downloaded and reviewed by a GP or specialist. These results will highlight any specific times of activity or rest that result in periods of hypertension. This can help your doctor establish an accurate diagnosis and give an indication of any potential underlying factors. 

If you receive a high blood pressure diagnosis, your consultant will comprehensively assess your future risk of developing cardiovascular diseases such as stroke, heart attack or kidney failure.

Further diagnostic tests

Depending on other symptoms you may be experiencing, your medical history and your specific blood pressure readings, your consultant might recommend further tests to diagnose or rule out any other cardiac condition. These might include: 

• Blood tests: These can detect high cholesterol and traces of proteins and blood sugars which can be signs of kidney issues, diabetes or heart disease.
• Urine tests: These can pick up proteins, blood, sugar and sodium in your urine, indicating how well your kidneys are performing and signs of diabetes or pre-diabetes.
• Electrocardiogram (ECG): This simple test can show how well your heart is working and can help detect arrhythmia, heart disease and thickened muscle walls.
• Echocardiogram: This is an ultrasound scan that provides detailed images of the heart and valves and shows any signs of damage.

High blood pressure treatment options

Depending on the severity of your high blood pressure and your overall health, you might be offered advice on making lifestyle changes or hypertension medication and/or treatment for any underlying conditions. 

How to reduce high blood pressure through lifestyle changes

In some cases, your consultant might recommend making healthy lifestyle changes such as:

• Lowering your salt intake
• Eating a balanced diet
• Increasing activity 
• Reducing your alcohol intake 
• Losing weight 
• Reducing your caffeine intake 
• Quitting smoking 
• Getting enough sleep 

Often, these steps will be advised alongside other treatments. 

High blood pressure medication 

Your consultant might prescribe medication to treat hypertension which could include one of the following (or a combination of): 

• Angiotensin-converting enzyme (ACE) inhibitors: These work by relaxing the blood vessels, resulting in lower blood pressure.
• Angiotensin-2 receptor blockers (ARBs): These also relax blood vessels and are often used if ACEs are causing side effects.
• Calcium channel blockers: This type of hypertension medication widens the blood vessels which reduces blood pressure.
• Diuretics: Treatment for high blood pressure sometimes involves taking diuretics which help to flush water and salt from the body. You might be prescribed these if you have signs of heart failure or you've had side effects from taking calcium channel blockers.
• Beta blockers: These medications can result in a lower, less forceful heartbeat, although they're not as commonly used as other drugs due to being considered less effective.

High blood pressure surgery

Occasionally, medication for hypertension might not work effectively. If this happens, it might be recommended that you have Endovascular Renal denervation (RDN). 

This is a minimally invasive procedure where a thin tube (a catheter) is inserted into the groin. Pulses are then passed through the tube to remove nerves in the renal artery wall near the kidney. With reduced overactivity in the renal artery, blood pressure is lowered.