The blood pressure is the pressure exerted by the blood on the walls of the arteries.

This pressure is expressed in the form of two values:

• the first, higher figure expresses the blood's pressure when the heart contracts and the blood flows out from it: this is the systolic pressure.
• the second, lower figure expresses the blood's pressure when the heart relaxes and fills with blood: this is the diastolic pressure.

Blood pressure is expressed in millimetres of mercury (mmHg).

The blood pressure can vary at different times of day, from day to day and under the influence of the emotions.

When a person's blood pressure values are constantly too high, he is said to suffer from arterial hypertension (AHT).

Normal and abnormal blood pressure values, as measured by your doctor or at the hospital:

• A systolic (SBP) and diastolic (DBP) blood pressure lower than 120/80 mmHg is optimal.
• A blood pressure lower than 130 mmHg systolic and 85 mmHg diastolic is still normal.
• A blood pressure between 130-139 mmHg systolic or between 85-89 mmHg diastolic is 'high-normal'. Beyond this:
  
  • mild AHT (grade 1) (SBP 140-159 or DBP 90-99)
  • moderate AHT (grade 2) (SBP 160-179 or DBP 100-109)
  • severe AHT (grade 3) (SBP > 180 or DBP > 110)
• Isolated systolic hypertension is an SBP > 160 mmHg and a DBP < 90 mmHg (very common in the over-60s).

Arterial hypertension can sometimes simply be due to the circumstances under which the blood pressure is measured.

If your blood pressure remains high while you are visiting the doctor, but returns to a normal level at home or during a blood pressure check, you are said to have "white-coat hypertension".

In 5% of cases, one of the following medical causes may be identified:

• a kidney disease;
• a hormonal condition;
• arterial damage;
• sleep disorders;
• medication (such as contraceptives or corticosteroids);
• excessive use of liquorice;
• obstruction of the respiratory passages (snoring) in overweight people.

Such cases are described as 'secondary hypertension'.

In the vast majority of cases (95%), the cause is unknown, and the person is said to suffer from 'essential hypertension'.

However, there are certain factors which promote arterial hypertension!

• Heredity: if your parents suffer from hypertension;
• Age: the risk of developing arterial hypertension increases with age;
• Gender: arterial hypertension mainly affects men over the age of 60. Women are often affected by hypertension after the menopause;
• Ethnic origin: people with darker skin colour are more likely to suffer from hypertension, and their hypertension is more likely to be resistant to treatment;
• Lifestyle: obesity, a sedentary lifestyle, excessive use of salt or alcohol, stress and smoking are factors which promote hypertension.

Yes. In older children and adolescents, the problem is often diagnosed as incipient essential arterial hypertension, like the hypertension that is commonly found in adults. In small children, arterial hypertension is often the consequence of a specific cause which requires a medical check-up.

The standard values for blood pressure are different for children and adolescents from those for adults. They depend on gender, age and body shape.

Blood pressure is measured after the patient has had 5 minutes' rest in a sitting position. The following rules apply:

• wait 30 minutes after drinking coffee or smoking cigarettes;
• the patient should not talk;
• the arm should be raised to the level of the heart and supported;
• the length of the cuff should be adjusted to the arm;
• the stethoscope should not be placed under the cuff;
• the point at which the heartbeat becomes audible is the systolic pressure; the point at which it ceases to be audible is the diastolic pressure;
• the blood pressure is sometimes also measured:
• on both arms (to detect diseases of the arteries);
• in a standing position (to rule out orthostatic hypotension which is very common in older patients, diabetes patients and Parkinson's disease patients). Orthostatic hypotension is an abnormal drop (=20 mmHg) in the systolic blood pressure when a patient stands up.

It is important for raised blood pressure to be confirmed by repeated measurements during the visit to the doctor or at the hospital before treatment is given for the condition.

Confirmation can also be obtained:

• by means of self-measurement: the measurement is performed by the patient at home (in his familiar setting);
• or using a portable sphygmomanometer (blood pressure meter): this device measures the blood pressure over 24 hours and allows the patient to move around.

Hypertension is often called 'the silent killer'.

This condition does not generally give rise to any complaints over a long period of time.

It is therefore important to have your blood pressure measured whenever you visit the doctor.

Raised blood pressure is sometimes accompanied by headaches, ringing in the ears and spots or 'flies' before the eyes, or may cause regular nosebleeds.

Hypertension is not really a disease: rather, it is a risk factor for cardiovascular diseases.

What this means is that an increase in blood pressure has been found to increase the likelihood of cardiovascular disease (heart attack, angina pectoris, stroke, etc.).

Hypertension is one of many risk factors, along with smoking, high cholesterol levels, diabetes, a sedentary lifestyle and so on.

The more risk factors there are, the greater the chance of cardiovascular disease.

While some risk factors cannot be treated or remedied, others such as hypertension can be kept under control.

If hypertension is not treated, it causes numerous health problems which may prove an enormous handicap to the patient and his family.

If hypertension is not treated, the blood vessels are affected (they become blocked). In other words, arterial hypertension promotes arteriosclerosis.

A number of organs may be affected (depending on which blood vessels are affected):

• The heart: if the arteries which supply the heart become blocked and the wall of the heart thickens, this causes complications such as angina pectoris, heart attacks and heart failure.
• The brain: the arteries which supply the brain may become blocked (cerebral thrombosis) or cause a brain haemorrhage. Both of these conditions can lead to paralysis, a coma or the death of the patient.
• The kidneys: if the arteries which supply the kidneys become blocked, you develop kidney failure and may need treatment with an artificial kidney.
• The eyes.
• The major blood vessels may become blocked - making it painful to walk - but can also dilate, leading to life-threatening haemorrhages.

Your doctor will determine how severe your hypertension is and perform a medical check-up:

• your doctorwill check whether the arterial hypertension has already damaged certain organs such as the heart, the kidneys, the brain (blood sample, urine test, electrocardiogram, ultrasound, eye examination);
• your doctorwill look for other risk factors which require appropriate treatment, such as diabetes, high cholesterol, smoking and obesity;
• your doctorwill investigate the cause of secondary hypertension and treat it (although this is extremely rare);
• your doctorwill investigate any conditions which may affect the prognosis or treatment (cancer, asthma, heart attack, etc.).

To prevent arterial hypertension, a number of habits may need to be modified.

• Slimming if you are overweight often has the same effect as taking a drug to lower the blood pressure. You should cut down on sugars and fats, eat more fruit and vegetables, eat at regular intervals, drink plenty of water and take more exercise.
• Reducing alcohol consumption: keep to an absolute maximum of 1 to 2 glasses of alcohol per day, and avoid alcohol completely on some days.
• Taking regular physical exercise (walking, cycling, jogging, etc.) is very good for you (at least 30 minutes per day). You should start out gradually and consult a doctor if you have any sports-related complaints.
• Ensuring a healthy diet with vegetables, fruit and low-fat dairy products.
• Reducing salt consumption: no more than 5g per day. Try to avoid using salt when preparing food and try low-salt foods, including low-salt bread.

Important measures which help reduce the risk of cardiovascular disease also include:

• giving up smoking;
• reducing fat consumption in your diet in order to lower your cholesterol level, another important risk factor for cardiovascular diseases;
• if indicated, using cholesterol-lowering drugs and/or aspirin.

Treatment with drugs to lower the blood pressure is generally supplemented with measures such as:

• weight loss if you are obese or overweight;
• changes to dietary habits (less salt, more fruit and vegetables);
• physical exercise;
• giving up smoking;
• reducing alcohol consumption (wine, beer, spirits, etc.).

If these health and dietary measures are not enough, you will need treatment with drugs (in addition to these measures!).

There are 9 groups of blood pressure-lowering drugs, and it is not unusual to have to take 2 to 4 different drugs at the same time:

• diuretics cause fluid and salt to be expelled via the kidneys;
• beta blockers reduce the nervous system's influence on the heart and blood vessels;
• calcium antagonists dilate the blood vessels by restricting the absorption of calcium in the vessel walls;
• angiotensin-converting inhibitors prevent the formation and action of the vasoconstrictor angiotensin II;
• angiotensin receptor blockers prevent angiotensin II from binding with its receptor, for instance in the artery walls or the kidneys;
• renin inhibitors are a new class of blood pressure-lowering drugs which inhibit the conversion of inactive angiotensin I into active angiotensin II;
• centrally acting antihypertensives lower the blood pressure by influencing the activity of certain centres in the brain;
• alpha blockers limit the action of certain hormones that constrict the blood vessels.

The doctor chooses the most suitable drug for a particular patient, taking account of the severity of the hypertension, the patient's lifestyle, the risk factors and any diseases.

The doctor will start with the lowest dose, but if the pressure does not fall sufficiently or if the patient exhibits side-effects, the doctor will switch to another drug. Thus it is not unusual for the doctor to try out several drugs before finding the drug or drugs that are best suited to the patient.

For more than 75% of patients, one drug is not enough to bring the blood pressure back to normal, and it will be necessary to add a second or even a third drug.

The treatment should reduce the systolic and diastolic blood pressure to below 140 and 90 mmHg respectively in the majority of patients suffering from arterial hypertension. The blood pressure values that need to be reached are lower in the case of diabetes or kidney disease.

The blood pressure-lowering drugs rarely cause side-effects. However, if this does happen, you should talk to your doctor as soon as possible so that the drug which is causing the problems can be replaced.

There are various drugs available which have the effect of lowering the blood pressure. Your doctor will choose the ones which suit you best. This sometimes requires a little patience, but it is one of the keys to success in treating arterial hypertension!

Yes. The various health and dietary measures have a positive effect on the blood pressure, but they are often insufficient to bring it back to normal. In general, when hypertension has definitely been diagnosed, the treatment needs to be followed for life. Blood pressure must be kept under 140/90 mmHg in all patients (or even lower in the case of diabetes or kidney conditions). The only way to obtain a permanent reduction of the blood pressure is to follow the treatment properly and regularly.

Failure to comply with the medical prescription often contributes to poor control of the blood pressure (only 25% of patients with hypertension have a systolic pressure <140 mmHg and a diastolic pressure <90 mmHg).

Moreover, the abrupt termination of the use of certain drugs which reduce the blood pressure can be dangerous to the health.

Definition

When the blood pressure is higher than or equal to 140 mmHg for the systolic blood pressure and/or 90 mmHg for the diastolic blood pressure, the patient is said to be suffering from hypertension or raised blood pressure. People with blood pressure at the lower limit of the normal values or below that limit are said to suffer from hypotension or low blood pressure, but there are no generally accepted minimum limits.

Primary hypotension

In primary or constitutional hypotension, no cause can be demonstrated. The blood pressure lies at the lower side of the bell-shaped distribution curve in the population.

Hypotension does not necessarily give rise to complaints, but may be associated with tiredness, a feeling of weakness and dizziness.

Low blood pressure tends to be a favourable prognostic factor for cardiovascular conditions, and does not represent a clinical problem if there are no symptoms.

Secondary hypotension

Low blood pressure may also the result of a demonstrable cause, such as a low circulating blood volume, cardiac conditions with a low cardiac output, diseases of the adrenal glands, cachexia or long-term confinement to bed.

Orthostatic hypotension

When you stand up, the blood volume in the lower limbs increases, causing a decrease in the return flow of blood to the heart and in the cardiac output, and hence in principle a fall in blood pressure.

However, the blood pressure remains sufficient as a result of the activation of the sympathetic nervous system and an increase in vascular resistance - since the blood pressure is the product of the cardiac output and the vascular resistance.

In orthostatic hypotension, an abnormal drop in blood pressure occurs when the person stands, defined as a drop in systolic pressure of more than 20 mmHg and in diastolic pressure of more than 10 mmHg. This may or may not have associated symptoms, giving rise in some cases to light-headedness, dizziness and even fainting (syncope) due to insufficient supply of blood to the brain.

The positional blood pressure drop may be caused by the blood volume being too low, by a dysfunction of the autonomous nervous system such as in diabetes, by extensive varicose veins, or by drugs such as diuretics, alpha blockers and nitrates. The fall in blood pressure when you stand up tends to be greater in older people than in young people, because their nervous system reacts more slowly or less efficiently to the reflux of blood to the lower limbs.

Treatment

Where there is a demonstrable cause, this is addressed as far as possible. A high-salt diet is a general measure. Only for people with numerous problems are blood pressure-raising drugs such as fludrocortisone prescribed; this drug causes the retention of salt and water in the kidneys and increases the blood volume.

Among the measures recommended for orthostatic hypotension are standing up more slowly and wearing tight elastic support stockings.