High Blood Pressure

Find a nutritionist dealing with High Blood Pressure »

Blood pressure measures the amount of force with which the blood presses against the artery walls as it pumps around the body.

Blood pressure increases naturally during physical activity or times of stress because adrenaline causes the heart to pump faster.

High blood pressure, otherwise known as hypertension, is when blood pressure remains at a consistently high level.

High blood pressure occurs if the heart is pumping too much blood, or if there is too much blood in circulation. When this occurs, the arterial walls contract too much, become narrowed and lose their elasticity. High blood pressure can lead to a number of serious complications such as:

  • damaged kidneys
  • damaged sight
  • cardiovascular diseases such as angina, stroke, heart failure, atrial fibrillation (irregular heart beat) and heart attack.

Causes of high blood pressure

High blood pressure is divided into two categories: primary hypertension and secondary hypertension.

Primary hypertension1

9 out of every 10 people who have high blood pressure have what is known as either primary hypertension or essential hypertension. Lifestyle and habits are the main causes of primary hypertension and these include:

  • obesity
  • smoking
  • unhealthy diet
  • lack of exercise.
  • excessive consumption of alcohol- especially binge-drinking.

Primary hypertension is more likely to affect those with family members who also have it.

Secondary hypertension1

Secondary hypertension is the less common of the two. 1 in every 20 people with high blood pressure has secondary hypertension. Secondary hypertension means that the high blood pressure can be linked to a known cause such as:

  1. A narrowed aorta or narrowing of the arteries, leading to the kidneys. The aorta is the largest artery leading from the heart.
  2. Kidney disease.
  3. Endocrine disease- a hormone disorder (hormones regulate the naturally occurring chemicals in the body).

Other causes of hypertension include:

  1. The contraceptive pill.
  2. Steroid medicines.
  3. Pregnancy- this can cause pre-eclampsia, which can be harmful to the unborn baby.

Diagnosing high blood pressure

High blood pressure tends not to have symptoms. It is therefore advisable to have regular medical check ups, especially for over 40s.

Blood pressure is measured with an instrument known as a sphygmomanometer.

A sphygmomanometer consists of a cuff attached to a monitor. The GP or nurse practitioner will wrap the cuff tightly around the upper arm with Velcro, and then inflate the cuff until it is tight enough to measure the blood pressing against the veins. 

The sphygmomanometer will produce two numbers: (e.g. 120/80mmHg (millimetres of mercury).

  1. The systolic blood pressure
    Systolic blood pressure is represented by the first number. It is the measurement taken when the heart muscle is contracted and pumping blood. The systolic blood pressure will be the highest pressure in the blood vessels.

  2. The diastolic blood pressure
    Diastolic blood pressure is represented by the second number. It is the measurement taken between heart beats when the heart is resting and filling with blood. The diastolic blood pressure will be the lowest pressure in the blood vessels.

A low blood pressure indicates good health. Doctors recommend a blood pressure of under 140/85.

If your blood pressure is found to be too high, the GP may refer you for some tests in order to determine whether or not the high blood pressure is affecting other areas of your body. Tests may include:

  1. A blood test- this determines cholesterol and blood sugar levels. It can also determine the condition of the kidneys.
  2. A urine test- this can determine the existence of a kidney problem
  3. An electrocardiogram (ECG)- this test measures the electrical activity in your heart and determines how well it is working.

Treating high blood pressure

High blood pressure cannot usually be completely cured. Instead, your GP may discuss some possible lifestyle changes that could make a difference. They may also prescribe certain medicines depending on the patient’s age and ethnicity. Often, prescribing the right medicine can be a case of trial and error. It can take time to find the right balance between the benefits of the medication and enduring the side-effects.

Lifestyle changes 

1.  Diet

There are certain foods that a doctor or nutritionist may advise you to eat in moderation if you have high blood pressure. These include-

  • Salt- eating too much salt can increase blood pressure and is often bad for the heart and kidneys.
  • Saturated fats- saturated fat can put extra strain on the heart and circulatory system which only serves to increase blood pressure.
  • Caffeine- drinking caffeine has been proven to increase blood pressure in the short term; however, there is no conclusive evidence that it affects blood pressure in the long term.

Doctors recommend a balanced diet. It is important to get enough of the right nutrients every day. These include:

  • Fibre, minerals and vitamins- found in fruit and vegetables.
  • Proteins- meat, beans and dairy.
  • Fats (unsaturated)- oily fish, nuts, meat,
  • Carbohydrates- pasta, rice, potato

It is advisable to always consult your GP if you plan to change your diet.

2.   Stop smoking

The chemicals found in cigarette smoke can cause blood vessels to narrow, increasing the risk of heart disease.  

3.  Cut down on alcohol

Drinking more than 21 units (for men) or 14 (for women) of alcohol per week could increase blood pressure. Try to adhere to the daily recommendations of a 125ml glass of wine (or equivalent) for women and 1 pint of beer (or equivalent) for men.

4.  Enjoy regular exercise

Exercising keeps the heart healthy and burns excess fat. Being overweight can put extra strain on organs and increases the risk of cardiovascular disease (angina, heart attack, stroke, heart failure). It is advisable to spend 30 minutes 3 times a week exercising moderately. Recommended forms of exercise include:

  • Cycling- cycling puts the least strain on joints. 30 minutes of cycling could burn 240 calories.
  • Swimming- like cycling, swimming is a low-impact activity that could burn an estimated 240 calories every 30 minutes.
  • Brisk walking- swapping driving for walking could dramatically improve your fitness levels and general health.

5. Cut down on caffeine 

Caffeine can cause a short but dramatic increase in blood pressure. It is advisable to cut down on things like tea, coffee, certain fizzy drinks and energy drinks. There are caffeine-free alternatives to all of these drinks.

Medication for high blood pressure

1. ACE Inhibitors (angiotensin converting enzyme)

What are ACE inhibitors?

ACE inhibitors are medicines designed to lower blood pressure, treat heart failure and help protect the kidneys (especially in the case of diabetes).

How do ACE inhibitors work?

The kidneys can detect when blood pressure drops in the body. When this happens, a chemical is released from the kidneys called angiotensin. When the angiotensin reaches the blood-supply and combines with the angiotensin-converting enzyme, the two substances become angiotensin II. Angiotensin II raises the dropped blood pressure by:

  1. Narrowing the blood vessels. When the same amount of blood passes through less space, the pressure increases.
  2. Releasing another hormone called aldosterone. Aldosterone instructs the body to retain water (which may otherwise pass through as urine). The extra water remains in the blood stream and thus increases the volume of blood running through the body. As with narrowing the blood vessels, more blood in less space increases the pressure in the body.

The medication ‘ACE inhibitors’ blocks angiotensin before it can combine with the angiotensin-converting enzyme. The ACE inhibitor prevents the angiotensin from becoming angiotensin II, meaning that the blood vessels will not narrow and the volume of blood will not increase, thus lowering the blood pressure.

How are ACE inhibitors taken?

ACE inhibitors are taken in the form of a tablet usually once a day, or as the GP advises. ACE inhibitors can often be taken with other heart and blood pressure medications.

What are the side effects of ACE inhibitors?

The most common side effect of taking ACE inhibitors is a dry cough. Patients may also feel dizzy when standing up. This is because the drug lowers blood pressure. Other less common side effects include:

  • hay fever-like symptoms such as a runny nose, itchy eyes and sneezing
  • a rash on the skin
  • swelling of the sinuses (sinusitis)
  • a sick feeling or actual vomiting
  • problems with bowels- diarrhea or constipation
  • sore throat
  • indigestion.

1 in 10 people have kidney problems as a result of taking ACE inhibitors2.

2. Calcium channel blockers

What are calcium channel blockers?

Calcium channel blockers are designed to lower blood pressure and alleviate the symptoms of angina (chest pains) by working on the muscle cells of the heart and arteries.

How do calcium channel blockers work?

Calcium blockers work in two different ways.

1) By targeting the heart: the heart functions via a series of electrical impulses passed from cell to cell. These impulses are then converted into chemical reactions inside the heart. Each signal carries different information and instructions. One signal carries information about calcium levels within the muscle cells and it is this signal that controls the contraction of the heart muscle. Calcium blockers restrict the flow of calcium into the heart muscle, thus lowering the amount of times the heart contracts.

2) By targeting blood vessels:  the calcium within the muscle cell controls the contraction of the muscle. The calcium channel blocker works by relaxing the walls of the blood vessels and widening the space through which the blood runs, thus alleviating the pressure.

How are calcium channel blockers taken?

Calcium channel blockers are only available on prescription from your GP. They tend to come as tablets or capsules and should be taken once or twice a day.

It is inadvisable to suddenly cease taking calcium channel blockers, as this can increase the symptoms of angina.

Different brands of calcium channel blockers can release at different paces so only one type should be taken at a time.

What are the side effects of calcium channel blockers?

Calcium channel blockers lower blood pressure and can therefore cause dizziness when moving from a sitting to standing position. It is advisable to stand up slowly next to a stable surface for extra support.

Calcium channel blockers can also slow the heart. This can cause:

  • headaches
  • fluid retention
  • facial flushing
  • constipation.

Always read the leaflet accompanying your medication

3) Thiazide diuretics

What are thiazide diuretics?

There are a number of different types of diuretics. Diuretics (otherwise known as ‘water tablets’) work to reduce the water content within the body by instructing the kidneys to produce more urine.

Thiazide diuretics are the most commonly prescribed form and are used to lower blood pressure, treat mild heart failure or severe oedema (bodily fluid retention).

How do thiazide diuretics work?

Diuretics reduce the amount of sodium and water released into the blood stream. As a result of this, the body produces more urine. This means the water levels in the blood are reduced. The bloodstream therefore decreases in volume and the heart no longer has to work so hard to pump blood around the body.

How are thiazide diuretics taken?

Because diuretics can remove potassium from the bloodstream, your GP may prescribe potassium supplements to take alongside your dose.

Diuretics are usually taken in tablet form, although some can be administered via an injection. The effects tend to last for 12 to 14 hours, therefore it is advisable to take the diuretics either in the morning or in the early afternoon. This is to prevent the excess urine produced by the kidneys from disturbing sleeping patterns.

What are the side effects of thiazide diuretics?

Elderly people are more likely to suffer from the side effects of taking diuretics. Pregnant women are warned not to take diuretics, as are sufferers of gout (a condition where crystals form in the joints). Diuretics can also increase sugar levels in the blood, which could lead to diabetes.

GPs will alter prescriptions accordingly and recommend regular blood and urine tests in order to monitor the effects of thiazide diuretics.

Side effects may include:

  • Altered level of certain minerals in the body, such as potassium and sodium. Supplements can be taken.
  • Dizziness caused by postural hypotension. Postural hypotension is a lowering of the blood pressure caused by body position.
  • Mild gastro-intestinal problems.

Less common side effects may include:

  • blood disorders that can heighten the risk of infection
  • rashes on the skin
  • impotence.

4) Beta-Blockers (beta-adrenoreceptor blocking drugs)

What are beta-blockers?

Beta-blockers are taken to treat a number of conditions. Firstly they can reduce the risk of a heart-attack patient suffering a repeat heart attack. Beta-blockers can also lower blood pressure and help treat a disturbed heartbeat rhythm (arrhythmia), migraine, glaucoma (eye condition) and heart failure.

How do beta-blockers work?

There is a chemical messenger in the body known as noradrenaline. Noradrenaline causes the arteries to narrow and this cause the heart to beat faster. Beta-blockers work by intercepting the noradrenaline at particular places in the body known as adrenoreceptors. These places are found in the arteries, on the heart muscle and on a number of other organs and muscles.

Beta-blockers are most effective when the heart is pumping fast during cardiovascular activity.

How are beta-blockers taken?

Beta-blockers are always prescribed by the GP and can come in a number of different forms including:

  • syrup or solution
  • injection
  • capsule or tablet

The effects of taking beta-blockers do not tend to last very long so the recommended dosage is usually 2 a day.

Stopping beta-blockers suddenly can increase the severity of a condition and its symptoms.

What are the side effects of beta-blockers?

Your GP may want to monitor you closely if you suffer from any of the following conditions:

  • heart failure
  • low blood pressure
  • slow heart rate
  • asthma or other respiratory problems
  • narrowing of the arteries that carry blood to the arms and legs (peripheral arterial disease).

Side effects of taking beta-blockers include: (there are many different types of beta-blocker and this list will not cover all. It is advisable to read the leaflet accompanying your prescription.)

  • tiredness
  • headache
  • cold sensation in hands and feet
  • impotence
  • nightmares or disturbed sleep
  • dizziness

Less common side effects can include:

  • visual disturbances
  • dry eyes
  • indigestion
  • wheezing
  • rashes on the skin

How can a nutritionist help with high blood pressure?

Monitoring your diet can be stressful and frustrating, especially when there is so much conflicting advice out there. Consulting a nutritionist can alleviate some of this pressure. A nutritionist understands how important a healthy diet is for maintaining a normal blood pressure. He or she will apply their expert knowledge to a personalised plan tailored to your medical requirements. If you would like to find a nutritionist, please use the search tool on our homepage.  

References

1 Bupa, High Blood Pressure - Hypertension

2 NHS, Coronary heart disease - Treatment

Back to Top
--

All content displayed on Nutritionist Resource is provided for general information purposes only, and should not be treated as a substitute for advice given by your GP or any other healthcare professional. Whilst some people have benefited from nutritional therapy, no claims can be made to treat, cure or heal specific conditions, and we strongly advise individuals with any health problem to seek independent medical advice from their GP before considering nutritional therapy.