Blood pressure: norms, reasons of high and low index, the treatment of hypertension and hypotension
The human body is the most complex mechanism of all. For its proper functioning, there are hundreds of parameters and constants, one of which is blood pressure. This is a very important component of homeostasis of the internal environment of the body. Blood pressure provides the necessary level of blood supply to all, without exception, organs. In the case of preferences that go beyond the physiological, in any direction (increase or decrease) develops a direct threat not only to the body's health, but for life. Because it is very important to have an idea of what it is, how is the pressure, which determines the physiological parameters of this indicator and the level of pressure that indicates the pathology.
What is blood pressure?
Arterial or systemic blood pressure (BP) is the pressure that the blood on the walls of blood vessels. Pressure is an important parameter of the living organism, in case of death the pressure falls to zero.
There are several types of systemic pressure:
- in the arteries – arterial (this is the indicator that is most often measured);
- in the capillaries – capillary;
- in the venous system – venous.
In practice often have to deal with blood pressure as the indicator easiest to measure (with help of a blood pressure cuff on the arteries of the shoulder). Measurement of capillary and venous pressure is invasive and complex procedures that can be conducted as needed in stationary conditions.
It should also be noted that the pressure which we measure with a cuff on the shoulder that is peripheral, or office, and does not fully reflect the true picture. There is still such a thing as Central blood pressure. This is the amount of pressure that exists at the level of the aorta (the largest blood vessel in the human body).
The Central pressure typically lower than peripheral (sometimes the rates differ quite significantly, for example, 20-30 mm Hg. calendar). Especially pronounced is the difference in people of young age group. With the years these numbers tend to equalize.
Central (aortic) pressure should act as a criterion when evaluating performance, but still not existed of non-invasive methods for its measurement and therefore in practice was the measurement of peripheral arterial pressure, the method which was proposed 100 years ago by surgeon Korotkov. However, today there is medical equipment for non-invasive measurement of Central blood pressure.
When measuring pressure record 2 digits,divided by a fraction. What do they mean? For example, 120/80 mm Hg. article Here the number 120 is called the systolic blood pressureand the top or heart. This is the maximum pressure in the arterial line, which occurs at the moment of maximum contraction of the heart (systole) and eject blood into the aorta. It primarily depends on the strength and frequency of heart contractions (the higher they are, the greater the figure shows the tonometer) and the resistance of the vascular wall at the moment.
Figure 80 represents diastolic blood pressurewhich is also called the lower or vascular. This is the minimum pressure in the vascular system, which is registered at the moment of maximum relaxation of the heart muscle (diastole). This figure depends only on the value of vascular resistance.
Also used in clinical practice indicators such as pulse pressure. It's the difference between systolic and diastolic pressure and normally it should be equal to 30-40 mm Hg. article
Blood pressure ensures the promotion of blood through the vessels, which makes possible the process of microcirculation and metabolism, the production of oxygen by all cells of the body. Any deviation from the norm leads to the violation of this mechanism and the development of severe consequences.
The mechanism of regulation of blood pressure
Maintain pressure at the required level there are 2 control systems:
- Nervous regulation – within the walls of the large arterial vessels are special receptors that detect blood pressure. If it does not correspond to the physiological norm, these receptors send nerve signals to the vasomotor center of the brain, where they are returned signal sent to the normalization of the pressure. For example, when the reduction in AD brain gives the command to vasoconstriction and increase their tone, increase cardiac output of blood and increased heart rate. All this leads to hemodynamic pressure. If it is necessary to reduce the commands of the brain are opposite – vasodilation, decrease peripheral resistance the blood, reducing the frequency and force of heart contractions.
- Humoral regulation, which exercises its influence on hemodynamics by allocating separate humoral substances (hormones). For example, in the case of a sharp pressure reduction the adrenal glands produce epinephrine, norepinephrine, glucocorticoid and mineralocorticoid hormones that lead to increased blood pressure. To maintain pressure at the required level is important to the renin-angiotensin system.
Alas, thosethe mechanisms that maintain blood pressure at a healthy body on a physiological level, and the presence of pathology or risk factors of hypertension lead to resistant high blood pressure with all facing the consequences.
How to interpret indicators?
Blood pressure depends on many factors, including:
- time of the day;
- emotional state;
- the position of the body in space (supine pressure is lower than horizontal);
- reception of psychoactive substances, certain medicines;
Blood pressure in humans varies over a wide range during the day, but usually it does not go beyond the accepted norms.
Indicators of AD in the adult shown in the table.
|Systolic blood pressure (mm Hg. article)||Diastolic blood pressure (mm Hg. article)||The indicator|
|140-159||90-99||Hypertension 1 degree|
|160-179||100-109||Hypertension 2 degree|
|More than 180||More than 110||Hypertension grade 3|
|More than 140||Less than 90||Isolated systolic hypertension|
|Less than 90||Less than 60||Hypotension|
In medical literature you can also meet such a diagnosis as “hypertension elderly”. In this case mainly increases systolic BP (isolated systolic hypertension). Usually affects people after the age of 65 years. Associated to this pathological condition mainly from a decrease in the elasticity and compliance of the vascular wall due to sclerotic changes, leading to increased peripheral resistance of the vascular wall and increase of pressure due to this component.When measuring blood pressure the doctor should take into account the existence of“white coat hypertension”. This is a false-positive reaction, which is manifested by increased pressure in response to emotional excitement associated with treatment to the doctor. In this case, the true pressure value may be much lower. To diagnose “white coat hypertension” needed for daily monitoring of pressure which occurs in the usualthe conditions of patients.
Often patients do not feel high blood pressure, according to statistics, only 50% of people with hypertension know about their disease. Natural is their main question: “is There a danger of high pressure in this case, and do you need treatment?”. The answer is definitely Yes! Indeed, the lack of symptoms does not reduce the risk of developing complications of hypertension.
Methods of blood pressure measurement
Today to measure blood pressure using 2 methods:
- The Method Of Korotkova.
- The oscillometric method.
The Method Korotkova
This technique of measuring blood pressure introduced into medical practice in 1905 surgeon Korotkov. This was designed simple device which we today call mechanical sphygmomanometer (cuff with bag, pressure gauge and a stethoscope). This method is most common because of its simplicity and low cost of the apparatus.
The method consists in clamping the cuff of the brachial artery and listening to the tones which occur with the gradual release of air from the cuff.
Despite all its advantages, the method Korotkova has its drawbacks:
- the method is rather subjective and depends entirely on the hearing, the person who does measurements;
- requires special training;
- depends entirely on the correct application of the apparatus and its location.
The oscillometric method
In this method of blood pressure measurement using electronic devices. The principle of their work is to record the pulse waves that are produced in the cuff during the passage of the portion of the blood through the compressed section of an arterial vessel.
This method is very easy to use, requires no special training, does not depend on the eyes and the ears of the person who conducts the measurements, and also can be used independently, without assistance.
Among the shortcomings can be noted:
- the device operates from batteries, which may give a false reading when the efflux of the period of validity of batteries;
- in this measurement the arm should be completely still, any movement distorts the result;
- the devices have a high enough price.
Rules of blood pressure measurement
The reliability of blood pressure monitors when measuring blood pressure to a large extent depends on how well made the measurements. Consider the basic rules of blood pressure measurement.
- Try to measure pressure at the same time as for day, this proportion varies in a wide range of values.
- Half an hour before the measurements do not drink caffeinated beverages and do not smoke.
- To measure blood pressure you needafter 5 minutes of rest in complete peace.
- The measurement is performed in a sitting position.
- All measurements should be carried out as instructions used by the apparatus.
- To apply the cuff you need at a certain level, as described in the instructions to the device.
- When measuring it is forbidden to move and to talk.
- The measurement is conducted 3 times with 1-3 minute break, the final result is taken the lowest value of 3.
- Spend measurements regularly HELL, all the results bring into a special diary this will help the doctor to find effective treatment).
- If you are overweight and the blood pressure cuff does not cover the arm, you must purchase a special device for obese people with cuff more.
Important! To measure the pressure needed on both hands. Normal indicators can vary in the range of 10 mm Hg. the article In the future, measurements of need and this is the hand that shows an elevated result.
Video on how to correctly measure blood pressure:
Arterial hypotension is a decrease in blood pressure below 90/60 mm Hg. article But this condition is not a disease, for example, in a completely healthy person this pressure can be recorded several times throughout the day.
The term “
Symptoms of hypertension
Long time hypertension occurs without overt symptoms and is generally detected incidentally during prophylactic examinations or when referring to the doctor about something else.
Among the symptoms that may indicate high blood pressure, should be highlighted:
- headache pulsating or bursting nature,
Pressure in children and adolescents
The child's body is characterized by the numbers pressure is lower than in adults. The younger the child, the walls of blood vessels more elastic, and the pressure in them below.
The table below shows the approximate values of normal pressure for children of different ages.
The age of the child Systolic blood pressure (mm Hg. article) Diastolic blood pressure (mm Hg. article) Up to 2 weeks 60-95 40-50 2-4 weeks 80-115 40-75 2-12 months 90-115 50-75 2-3 years 100-115 60-75 3-5 years 100-115 60-75 6-9 years 100-125 60-80 10-12 years 110-125width="234">70-85 13-15 years 110-135 70-85
High blood pressure the child should always be alert, because the children do not get sick of primary arterial hypertension. Because the cause of high blood pressure lies in the other diseases. Most often it is:
- congenital or acquired diseases of the kidneys and other organs of the excretory system;
- diseases of endocrine organs;
- congenital malformations of the cardiovascular system.
In adolescence the reason for the increase in pressure may be a dysfunction of the autonomic nervous system. For this disorder characterized by alternating periods of high and low pressure.
High blood pressure in pregnant women
High blood pressure during pregnancy is a very dangerous condition for both the mother and her unborn child. The woman can be ill with hypertension before pregnancy, but most often pressure increases during pregnancy, usually after 20 weeks of gestation, and due to the development of complications of pregnancy, late gestosis (preeclampsia and eclampsia).
The danger of this condition is in violation of placental blood flow that can lead to premature birth, bleeding, placental abruption, intrauterine fetal death, placental insufficiency.
Treatment of high blood pressure during pregnancy is a very difficult task, since most of the medication women are in the position contraindicated.
Current recommendations for therapy of high blood pressure in pregnancy:
- in the case of danger to woman's life can be carried out termination of pregnancy for medical reasons, hypertension itself is not an indication for interruption of pregnancy;
- medications are not administered in the first trimester of pregnancy (only in emergencies, when the benefit to the mother outweighs the harm to the fetus);
- medication is used at higher pressure above 150-160/100-110 mm Hg. article, it is at this level is a violation of placental blood flow;
- pregnancy of an antihypertensive medication used only Dopegit, Nifedipine, Clonidine, Labetalol, Atenolol, Metoprolol.
Video about high blood pressure in pregnancy:
Principles of treatment of hypertension
Treatment of hypertension is a complex task that requires the patient first and foremost, discipline and patience. Therapy should be integrated (pharmacological and non-pharmacological) aimed not only at reducing the numbers of pressure, but for prevention of pathological changes in target organs, the elimination of other risk factors for cardiovascular disease (Smoking, elevated atherogeniccholesterol, overweight, lack of exercise, chronic stress, poor diet, age).
Modern drug treatment of hypertension
Today, there are a large number of medicines for the treatment of arterial hypertension who meet the basic requirements: they are safe with daily use, effectively control blood pressure, their duration reaches a day or more, not only reduce pressure, but also protect target organs from damage.
There are 5 major groups of medications for the treatment of hypertension:
- Diuretics (furosemide, torasemid, indapamide, gidrokhlorisiazit, chlortalidone) – they reduce the number circulating in the vessels, fluid, and reduce pressure. Are the drugs for the treatment of hypertension if no contraindications to their use, for example, diabetes, gout.
- ACE inhibitors (captopril, enalapril, lisinopril, ramipril, perindopril, fosinopril) drugs of this group inhibit the formation of substances such as angiotensin-2, which is a powerful vasoconstrictor agent. As a result, the vessels dilate and the pressure drops.
- Sartan, or blockers of receptors of angiotensin (losartan, valsartan, telmisartan) – these drugs block receptors for angiotensin, which leads to the loss of its vasoconstrictor abilities and reduce pressure.
- Beta-blockers (bisoprolol, nebivolol, atenolol, metoprolol) – they reduce the heart rate, which leads to a decrease in minute volume of blood flow and lowering blood pressure.
- Calcium channel blockers (amlodipine, nifedipine, verapamil, diltiazem, lercanidipine) – drugs from this group, expanding peripheral vessels, which leads to a decrease in peripheral vascular resistance and reduction in blood pressure.
The necessary drug and its dosage selects only the doctor as all medications have side effects and contraindications. In most cases, apply not one but several medications from different groups. The modern pharmaceutical market there is a combination of drugs two and three, which significantly improves compliance, convenience for the patient when receiving medication).
In order to effectively control your blood pressure, it is necessary once and for all get rid of the following misconceptions about hypertension:
- high blood pressure – it is normal for people in the older age group (no such thing according to the official medicine, the pressure should be within normal values listed above, regardless of gender and age);
- to treat hypertension can be episodic or courses (onlydaily consumption of prescribed medication can keep your blood pressure within the physiological norm, if you are diagnosed with hypertension);
- treatment should be aimed only at reducing the numbers of pressure (therapy must include methods that prevent the development of complications of hypertension);
- the ability to choose a blood pressure medicine (only experienced professional after a thorough examination will be able to prescribe the necessary drugs, self-medication is strictly prohibited);
- in any case it is impossible to refuse non-pharmacological treatment of hypertension (sometimes a lifestyle modification, getting rid of excess pounds leads to a normalization of pressure and no need to take medication).
Remember that the desired level of blood pressure should be below 130/85 mm Hg. article Only in this case, therapy can be considered effective and the patient is protected from the adverse effects of chronic high blood pressure.