Disease definition. Causes of the disease
The main criterion for arterial hypertension (hypertension) as a whole group of diseases is a stable, that is, detected with repeated measurements on different days, increase in blood pressure (BP).
The question of what exactly BP should be considered elevated is not as simple as it may seem. The fact is that among practically healthy people, the range of BP values is quite wide. Results of long-term observation of people with different levels of BP have shown that starting from the level of 110-115/70-75 mm Hg, each additional increase in BP by 10 mm Hg is accompanied by an increased risk of developing cardiovascular diseases (primarily ischemic heart disease and stroke). However, the benefit of modern methods of treating hypertension has been proven mainly for those patients whose BP exceeded 140/90 mm Hg. It is for this reason that it was agreed to consider this threshold value as a criterion for diagnosing arterial hypertension.
Elevations in blood pressure can be accompanied by dozens of different chronic diseases, and hypertensive disease is just one of them, but the most common: approximately 9 out of 10 cases. The diagnosis of “hypertensive disease” (HD) is established in cases where there is a stable increase in BP, but at the same time no other diseases that lead to an increase in BP are detected. Hypertensive disease is a disease for which a stable increase in BP serves as its main manifestation. Risk factors increasing the likelihood of its development have been identified during observations of large groups of people. In addition to genetic predisposition in some people, among such risk factors are:
• Excess body weight and obesity;
• Sedentary lifestyle;
• Excessive consumption of table salt, alcohol;
• Chronic stress;
• Smoking.
In general, all the characteristics that accompany the modern urban lifestyle in industrially developed countries. It is for this reason that hypertensive disease is considered a lifestyle-related disease, and its targeted improvements should always be considered within the framework of the hypertensive disease treatment program in each individual case.
What other diseases are accompanied by an increase in blood pressure?
These include many kidney diseases (pyelonephritis, glomerulonephritis, polycystic kidney disease, diabetic nephropathy, renal artery stenosis, etc.), a number of endocrine diseases (adrenal tumors, hyperthyroidism, Cushing’s disease and syndrome), obstructive sleep apnea syndrome, and some other, rarer diseases.
Regular use of medications such as glucocorticoids, nonsteroidal anti-inflammatory drugs (NSAIDs), oral contraceptives, can also lead to persistent hypertension.
The above diseases and conditions lead to the development of so-called secondary, or symptomatic, arterial hypertension. A doctor establishes the diagnosis of hypertensive disease if, during a conversation with the patient, clarification of the history of the disease, examination, as well as the results of some, mainly uncomplicated, laboratory and instrumental methods of examination, the diagnosis of any of the secondary arterial hypertension appears unlikely.
Symptoms of arterial hypertension
Elevated blood pressure itself is not accompanied by any subjective sensations in many people. However, if it is accompanied by symptoms, it can include a feeling of heaviness in the head, headaches, flickering before the eyes, nausea, dizziness, unsteadiness when walking, and a number of other symptoms, which are quite nonspecific for elevated blood pressure as they can occur with various other conditions. The above-mentioned symptoms are much more pronounced during a hypertensive crisis – a sudden significant increase in blood pressure, leading to a noticeable deterioration in the condition and well-being.
It could be further listed through a comma possible symptoms of hypertensive disease, but there is little benefit in doing so. Why? Firstly, all these symptoms are nonspecific (i.e., they can occur both separately and in various combinations with other diseases), and secondly, the fact of stable elevation of blood pressure is important for diagnosing arterial hypertension. This is not detected by assessing subjective symptoms, but only by measuring blood pressure, and not just once. It means, firstly, that blood pressure should be measured twice or thrice (with a short break between measurements) during one sitting, and the true blood pressure should be taken as the arithmetic mean of the two or three measured values. Secondly, the stability of blood pressure elevation (a criterion for diagnosing hypertensive disease as a chronic condition) should be confirmed during measurements at two doctor’s visits, preferably with an interval of at least a week.
In the case of a hypertensive crisis, symptoms will be present, otherwise it is not a hypertensive crisis but simply asymptomatic elevated blood pressure. And these symptoms can be both those listed above and others, more serious ones, which are discussed in the “Complications” section.
Symptomatic (secondary) arterial hypertension develops within the framework of other diseases, and therefore its manifestations, in addition to the actual symptoms of elevated blood pressure (if any), depend on the underlying disease. For example, with hyperaldosteronism, it can be muscle weakness, cramps, and even transient (lasting hours to days) paralysis in the muscles of the legs, arms, neck. In obstructive sleep apnea syndrome, symptoms can include snoring, breathing pauses during sleep, daytime sleepiness.
If hypertensive disease over time (usually many years) leads to damage to various organs (referred to as “target organs” in this context), it can manifest as memory and intellect decline, stroke or transient ischemic attack, thickening of the walls of the heart and, as a result, development of heart failure, accelerated formation of atherosclerotic plaques in the blood vessels of the heart and other organs, myocardial infarction or angina, decreased blood filtration rate in the kidneys (renal insufficiency), etc.
Additionally, complications arising from long-term hypertension may include damage to the eyes (such as retinopathy), leading to vision problems or even blindness, as well as kidney damage (nephropathy), potentially leading to chronic kidney disease or kidney failure.
Moreover, hypertension can exacerbate existing health conditions, such as diabetes, by worsening insulin resistance and increasing the risk of cardiovascular complications.
In summary, while hypertension may initially present with subtle or nonspecific symptoms, its long-term effects on various organs and systems can have significant and far-reaching consequences. Therefore, early detection, management, and control of blood pressure are essential for preventing complications and maintaining overall health and well-being.
Classification and stages of development of arterial hypertension
Hypertensive disease, depending on the magnitude of elevated blood pressure, is divided into three degrees. Additionally, considering the increased risk of cardiovascular diseases over years or decades, several gradations of blood pressure levels are distinguished.
Classification of blood pressure levels based on measurements taken in the clinic:
| Category | Systolic BP (mmHg) | Combination of Indicators | Diastolic BP (mmHg) |
|---|---|---|---|
| Optimal | < 120 | and | < 80 |
| Normal | 120–129 | and/or | 80–84 |
| High normal | 130–139 | and/or | 85–89 |
| Stage 1 hypertension | 140–159 | and/or | 90–99 |
| Stage 2 hypertension | 160–179 | and/or | 100–109 |
| Stage 3 hypertension | ≥ 180 | and/or | ≥ 110 |
| Isolated systolic hypertension | ≥ 140 | and/or | < 90 |
If the values of systolic and diastolic blood pressure fall into different categories, the degree of hypertension is assessed based on the higher of the two values, regardless of whether it is systolic or diastolic. The degree of blood pressure elevation in diagnosing hypertensive disease is determined during measurements at two different doctor’s visits.
Stages of arterial hypertension are still distinguished, while European guidelines for the diagnosis and treatment of arterial hypertension do not mention any stages. The delineation of stages aims to reflect the progression of arterial hypertension from its onset to the appearance of complications.
These stages are three:
- Stage I implies that there is no obvious damage to the target organs typically affected by this disease: there is no enlargement (hypertrophy) of the left ventricle of the heart, no significant decrease in kidney filtration rate, no presence of albumin protein in the urine, no thickening of the walls of the carotid arteries or atherosclerotic plaques in them, no changes in the fundus of the eye, etc. The only thing that can be confirmed is periodic or persistent elevation of blood pressure.
- If there is at least one of the listed signs of target organ damage, but these abnormalities are asymptomatic, stage II arterial hypertension is diagnosed.
- Finally, stage III arterial hypertension is diagnosed when there is at least one cardiovascular disease with clinical manifestations associated with atherosclerosis (myocardial infarction, stroke, angina pectoris, atherosclerotic leg artery disease), or, for example, diabetes mellitus with target organ damage and/or severe kidney damage, manifested by a significant decrease in filtration and/or significant loss of protein in the urine.
These stages do not always successively replace one another: for example, a person may initially have a heart attack and then, after several years, develop elevated blood pressure. In this case, the patient has stage III hypertensive disease.
The purpose of distinguishing stages is mainly to rank patients according to the degree of risk of cardiovascular complications. Treatment measures depend on this risk: the higher the risk, the more intensive the treatment. Risk assessment at the time of diagnosis is made using four gradations, with the 4th grade corresponding to the highest risk.
Complications of arterial hypertension
The goal of treating hypertensive disease is not simply to “lower” elevated blood pressure but to minimize the risk of long-term cardiovascular and other complications. This risk increases with every additional 10 mmHg from a blood pressure level of 115/75 mmHg, as assessed over years or decades. Complications include stroke, ischemic heart disease, vascular dementia (cognitive impairment), atherosclerotic leg artery disease, chronic kidney disease, and chronic heart failure.
Many patients with hypertensive disease may not experience any symptoms for a while, which can lead to a lack of motivation to undergo treatment. However, treating hypertensive disease requires ongoing efforts, including regularly taking specific medications and adopting a healthier lifestyle. There are no one-time measures in the treatment of hypertensive disease that would allow one to forget about the condition permanently without taking any further action.
Diagnosis of arterial hypertension
As for the diagnosis of arterial hypertension itself, it usually proceeds quite simply: it only requires repeatedly recorded blood pressure at or above 140/90 mmHg. However, hypertension and arterial hypertension are not the same thing: as already mentioned, a whole range of conditions can manifest as elevated blood pressure, and hypertension is just one of them, albeit the most common. When diagnosing, the physician, on the one hand, needs to ensure the stability of the elevated blood pressure, and on the other hand, to assess the likelihood that the elevated blood pressure is a manifestation of symptomatic (secondary) arterial hypertension.
To do this, in the initial stage of diagnostic search, the physician determines at what age the blood pressure first began to rise, whether there are symptoms such as snoring with sleep apnea, episodes of muscle weakness, unusual urinary components, sudden palpitations with sweating and headache, etc. It makes sense to inquire about the medications and supplements the patient is taking, as in some cases, they may lead to elevated blood pressure or exacerbate existing hypertension.
Several routine diagnostic tests (performed on almost all patients with elevated blood pressure), along with information obtained during the conversation with the physician, help to assess the probability of certain forms of secondary arterial hypertension: urinalysis, determination of blood creatinine and glucose concentrations, and sometimes potassium and other electrolytes.
Overall, given the low prevalence of secondary forms of arterial hypertension (about 10% of all cases), there needs to be substantial evidence to justify further search for these conditions as a possible cause of elevated blood pressure. Therefore, if significant data supporting the secondary nature of hypertension are not found in the initial stage of diagnostic search, it is considered that the elevated blood pressure is due to hypertension. This judgment may sometimes be reconsidered as new information about the patient becomes available.
In addition to searching for data on the possible secondary nature of elevated blood pressure, the physician determines the presence of cardiovascular risk factors (necessary for prognosis assessment and a more targeted search for internal organ damage), as well as possibly existing cardiovascular diseases or their asymptomatic damage — this affects the prognosis assessment and stages of hypertension, the choice of therapeutic measures. For this purpose, in addition to the patient interview and examination, a series of diagnostic tests are performed, such as electrocardiography (ECG), echocardiography (EchoCG), ultrasound examination (US) of the neck and head vessels, and, if necessary, other tests, the nature of which is determined by the medical data already obtained about the patient.
24-hour blood pressure monitoring using special compact devices allows to assess blood pressure changes during the patient’s usual lifestyle. This study is not necessary in all cases — mainly, if the blood pressure measured at the doctor’s office significantly differs from that measured at home, if there is a suspicion of hypotension episodes, sometimes — to assess the effectiveness of the ongoing treatment.
Thus, some diagnostic methods in examining patients with elevated blood pressure are applied in all cases, while the application of other methods is more selective, depending on the medical data already obtained about the patient, to check the assumptions that arose during the preliminary examination by the physician.
Treatment of arterial hypertension
Regarding non-pharmacological measures aimed at treating hypertension, the most compelling evidence has been accumulated on the positive role of reducing salt intake, maintaining or reducing body weight, regular physical exercise, moderate alcohol consumption, and increasing the intake of vegetables and fruits. However, all these measures are effective as part of long-term changes to the unhealthy lifestyle that led to the development of hypertension. For example, a 5 kg weight loss led to an average decrease in blood pressure of 4.4/3.6 mmHg — seemingly small, but in combination with other lifestyle improvements listed above, the effect can be significant.
Lifestyle modification is justified for almost all patients with hypertension, whereas pharmacological treatment is indicated, though not always, in most cases. Medication is mandatory for patients with stage 2 and 3 hypertension, as well as for those with any degree of hypertension with high calculated cardiovascular risk (its long-term benefit has been demonstrated in many clinical trials). However, for patients with stage 1 hypertension and low to moderate calculated cardiovascular risk, the benefit of such treatment has not been convincingly demonstrated in serious clinical trials. In such situations, the potential benefit of medication is assessed individually, taking into account the patient’s preferences.
If despite lifestyle changes, blood pressure remains elevated in these patients during repeated visits to the doctor over several months, the need for medication should be reassessed. Moreover, the calculated risk level often depends on the thoroughness of patient evaluation and may be significantly higher than initially estimated.
In almost all cases of hypertension treatment, the goal is to achieve blood pressure stabilization below 140/90 mmHg. This does not mean that blood pressure will be below these values in 100% of measurements, but the less frequently blood pressure exceeds this threshold under standard conditions (described in the “Diagnosis” section), the better. Thanks to such treatment, the risk of cardiovascular complications is significantly reduced, and hypertensive crises, if they occur, happen much less frequently than without treatment. Due to modern medications, the negative processes that inevitably and insidiously damage internal organs over time in hypertension are slowed down or halted, and in some cases, even reversed.
The main classes of medications for treating hypertension are:
– Diuretics;
– Calcium channel blockers;
– Angiotensin-converting enzyme inhibitors (names ending in “-pril”);
– Angiotensin II receptor blockers (names ending in “-sartan”);
– Beta-blockers.
In recent years, particular emphasis has been placed on the role of the first four classes of medications in treating hypertension. Beta-blockers are also used, but mainly when their use is required for concomitant conditions — in these cases, beta-blockers serve a dual purpose.
Nowadays, combinations of medications are preferred in hypertension treatment, as treatment with a single medication rarely achieves the desired blood pressure level. There are also fixed combinations of medications that make treatment more convenient since the patient takes only one tablet instead of two or even three. The selection of the necessary classes of medication for a specific patient, as well as their doses and frequency of intake, is done by the physician considering the patient’s data, such as blood pressure level, comorbidities, etc.
Thanks to the multifaceted positive effects of modern medications, the treatment of hypertension involves not only reducing blood pressure itself but also protecting internal organs from the negative effects of processes accompanying elevated blood pressure. Furthermore, since the main goal of treatment is to minimize the risk of complications and increase life expectancy, it may be necessary to adjust cholesterol levels, take medications to reduce the risk of thrombosis (which leads to heart attacks or strokes), etc. Quitting smoking, as banal as it may sound, allows a significant reduction in the risks of stroke and heart attack associated with hypertension, and slows down the growth of atherosclerotic plaques in the vessels.
Thus, the treatment of hypertension involves addressing the disease from multiple angles, and achieving normal blood pressure is just one aspect of it.