High Blood Pressure: Natural Self-help for Hypertension, including 60 recipes

CHAPTER 1 What is High Blood Pressure?

Everyone needs a certain blood pressure (BP) to keep blood moving around their body and maintain their circulation. Blood pressure exists because your heart pumps blood around a closed system, rather like a boiler pumping water through a series of central heating pipes. The pressure in your arteries therefore depends on a number of factors, including the volume of fluid inside your circulation, how hard your heart is pumping at any given time, and the elasticity or ‘resistance’ of the vessels the blood is passing through.

Normal BP varies naturally throughout the day and night, going up and down in response to your emotions and level of activity. If you have high blood pressure, however, your BP will remain consistently high, even when you are asleep.

The heart alternately contracts and relaxes as it pumps to produce the heartbeat. Each contraction produces a surge in pressure. The highest pressure reached in the arteries during this surge is known as the systolic pressure as it is due to contraction (systole) of the heart. As the heart rests between beats, blood pressure falls again and the lowest blood pressure recorded while the heart rests (diastole) is known as the diastolic pressure. In general, as the heart pumps more strongly, systolic pressure rises, while a reduction in elasticity of the peripheral arteries causes diastolic pressure to go up.

How BP is Measured

Blood pressure (BP) is measured using an instrument called a sphygmomanometer. This has an inflatable cuff which goes around your upper arm, a small pump to push air into the cuff and a column of mercury (or a dial) to record the pressure within the cuff.

As the cuff is inflated with air, the person measuring your BP usually feels for a pulse (brachial artery) in the crook of your elbow. While the pressure within your artery stays higher than that in the cuff, blood can be felt pulsing through. Once the pressure in the cuff becomes greater than that in your artery, the vessel is squashed flat and blood stops flowing through it at that point. By inflating the cuff to an initial pressure that is higher than the expected systolic pressure, then listening with a stethoscope over your brachial artery as the pressure is slowly released, the point at which blood manages to squirt through again with each pulse can be heard distinctly as a tapping sound. The pressure registering in the cuff at this point is taken as your systolic BP. The cuff is then slowly deflated further while listening over your artery. The tapping sounds become louder, then change to a dull whooshing noise before disappearing. The point at which blood can no longer be heard whooshing through the vessel is taken as your diastolic BP. The pulsing noise heard in the artery between these two pressures is a result of turbulence as the cuff impinges on the vessel and deforms its walls. We therefore know that the blood pressure in the artery is the same as that in the cuff at the point where the sounds disappear, as turbulence is no longer occurring. BP can also be measured with modern digital cuffs that fit around the wrist.

BP is measured according to the length of a column of mercury it can support. It is therefore expressed in millimetres of mercury (mmHg). BP is written down as the higher pressure (systole) over the lower figure (diastole).

How Blood Pressure is Controlled

Blood pressure is normally controlled and kept within safe limits by the body in a number of ways, including:

These factors are controlled by nerve signals from the brain, and by several different hormones. As a result, normal BP varies naturally throughout the day, going up and down in response to your emotions and level of activity. It is lowest during sleep (usually at around 3am) and highest in the morning from just before you wake until around 11 am. If you have high blood pressure, however, your BP will remain high all the time, even at rest.

Hypertension

As many as one in five adults have high blood pressure, known medically as hypertension. This means that blood is forced through their system under a constantly high pressure. Hypertension is diagnosed when systolic pressure is consistently greater than 140 mmHg and diastolic pressure consistently greater than 90 mmHg. A systolic blood pressure between 140–160 mmHg and diastolic values between 90–95 mmHg are sometimes referred to as mild hypertension.

In hypertension, the body’s systems for correcting high or low blood pressure don’t seem to work properly so blood pressure is maintained at an elevated level compared to normal. Little is known about how or why this happens, but the condition seems to be readily reversible once diet and lifestyle changes are introduced, together with any necessary anti-hypertensive drug treatment.

SYMPTOMS

Unfortunately, people with high blood pressure usually notice very little in the way of symptoms, although a few may develop a pounding sensation in their ears or a splitting headache. As a result, hypertension is often referred to as the silent killer, as it usually creeps up on you without any obvious warning. Even if your blood pressure is dangerously high, you may feel relatively well. If symptoms do occur, they tend to be non-specific, such as a headache or getting up at night to pass urine more often than normal. Your blood pressure has to be severely raised before you develop dizziness or visual disturbances. It is therefore a good idea for adults to have their blood pressure checked on a regular basis, every year or so – especially if high blood pressure runs in their family. This is because a high blood pressure that remains undiagnosed and untreated can lead to a number of potentially serious complications.

WHY HIGH BLOOD PRESSURE IS HARMFUL

Hypertension is not a disease in itself, but a clinical sign that you are at increased risk of a number of serious health problems. As blood is forced through your system at high pressure, your artery walls receive a pounding. This which can both over-stretch important blood vessels as well as damage their linings. If left untreated, this can trigger premature hardening and furring up of the arteries (atherosclerosis) and increase the risk of a number of health problems. If your blood pressure remains constantly high, this can lead to:

Research shows that for a man in his 40s:

This all sounds rather frightening, but the good news is that early diagnosis and treatment can control your blood pressure and keep you healthy. It is vitally important that your hypertension is well controlled, by taking your tablets exactly as prescribed. A number of relatively simple dietary and lifestyle changes can also help to reduce the risk of high blood pressure, lower a BP that is already raised and reduce the risk of complications such as coronary heart disease. If these changes were to reduce your diastolic BP by as little as 5 mmHg, they would decrease your risk of coronary heart disease by 16 per cent, and if they succeeded in reducing your average blood pressure by 10 mmHg, this would reduce your risk of premature death by as much as a third. You really can eat to beat the unwanted effects of high blood pressure.

UNDIAGNOSED HYPERTENSION

Ideally, all adults should have their blood pressure measured regularly, at least once every three years, or more often as your doctor recommends. If your blood pressure is found to be high, you will have it measured several times before your doctor decides whether or not to prescribe any anti-hypertensive drugs. This is to make sure your blood pressure remains consistently high and is not just going up as a result of visiting the surgery. Once you start taking blood pressure treatment, you may be on it for life – but you will probably live longer as a result.

Unfortunately, an estimated one in two people with high blood pressure are undiagnosed, and of those that are picked up and treated, at least another half do not have acceptable blood pressure control. This is mostly because the condition rarely makes you feel ill, and having to take one, two or even three tablets per day to treat something that is not an illness, but a risk factor for other diseases, is understandably frustrating. However, early diagnosis and successful treatment of high blood pressure is vital for continued long-term health.

Types of High Blood Pressure

Ninety per cent of people with high blood pressure, have no obvious single cause and are said to have primary, or essential, hypertension. The remaining one in ten people with high blood pressure have an identifiable underlying factor, such as kidney problems, a hormone imbalance or drug side-effects, and are said to have secondary hypertension.

Malignant hypertension refers to the most dangerous type of high blood pressure in which pressures go very high, often very quickly. This can damage internal organs over a short period of time and is sometimes also referred to as accelerated hypertension. It is treated as a medical emergency because if diastolic pressure remains above 120 mmHg for a prolonged period of time, the linings of small blood vessels (arterioles) are damaged and start to leak. When looked at under the microscope, the blood vessel walls have literally started to crumble (fibrinoid necrosis). This lets protein-rich fluid, and sometimes whole blood, seep out of the blood stream to build up in the tissues. As well as interfering with blood supply to that part of the body, the leakages cause damage, inflammation and scarring – commonly to the kidneys, backs of the eyes and in the brain. This is known as target organ damage. Damage to the kidneys also results in the release of hormones that put the blood pressure up even more, so a vicious cycle builds up. Treatment aims to bring BP down slowly over several days so that the body can adjust to lower pressures again.

To differentiate it from malignant hypertension, primary high blood pressure is often referred to as benign essential hypertension.

Refractory hypertension refers to high blood pressure that does not respond to standard first-line anti-hypertensive drug treatments. Although this is uncommon, referral to a specialist is needed so that investigations and treatment with other drugs can be started.

CHAPTER 2 Causes, Diagnosis and Treatment of High Blood Pressure

Blood pressure naturally tends to rise with age, so that high blood pressure is more common in middle life and beyond. Some people, especially males, may develop it in their 20s or even earlier, however. Blood pressure is also known to vary with race – those of African origin tend to have higher blood pressures than Caucasians, for example.

Causes of Essential Hypertension

Several factors are thought to be involved in the development of primary, or benign essential hypertension. These include inherited factors (high blood pressure runs in some families), developmental factors (occurring during embryonic life in the womb) and environmental factors such as diet and lifestyle, which you can address to help lower a high blood pressure.

INHERITED FACTORS

Essential hypertension is thought to result from inherited genes that may trigger high blood pressure as a result of one or more abnormalities involving:

Researchers have already identified a gene that may be able to predict your future risk of hypertension. People who have inherited the angiotensinogen gene (T235) from both parents have double the risk of developing high blood pressure and coronary heart disease compared to those who do not have the gene variant, or who inherit it only from one parent.

DEVELOPMENTAL FACTORS

Fascinating research has suggests the way you develop during the first few weeks of life as an embryo may affect your future risk of high blood pressure and other cardiovascular diseases in adult life. This is probably linked with lack of micronutrients (vitamin and minerals) in the mother’s diet, which affects the way your arteries are laid down. Researchers have found, for example, that:

– as a baby’s birth length decreases

– as the ratio of a baby’s head circumference to the length of the baby increases from less than 0.65 to 0.7 or more.

– if the mother’s blood haemoglobin level was low during pregnancy

– if maternal nutrition was known to be poor.

Lack of important nutrients – including vitamins, minerals and essential fatty acids – during the first few weeks of embryonic life is thought to trigger the development of abnormal arterial and blood circulatory patterns. These probably result from an imbalance between the placenta and baby. This is supported by research linking fingerprint patterns with the risk of developing high blood pressure in later life. Fingerprints are laid down in the womb in the first few weeks following conception. Their patterns are linked to the degree of bumpiness and swelling of the developing fingertips, which is related in turn to irregular blood circulation.