The increased pressure in the arterial blood vessels is called high blood pressure (hypertension). Doctors refer to the disease as “arterial hypertension” or hypertension. The opposite of this is mostly harmless low blood pressure (hypotension).
This is how blood pressure is created
The blood is expelled from the heart through the aortic valve into the arteries. The pressure of the flowing blood on the walls of the blood vessels (arterial walls) is called blood pressure. The level of blood pressure depends on the pumping capacity of the heart and the diameter of the vessels.
With physical exertion or excitement, blood pressure rises, while at rest it falls again. Within certain limits, this is completely normal and also desirable. Permanently high blood pressure, that is, even at rest, is unhealthy. The definition of when blood pressure is too high is set by the World Health Organization (WHO).
Measure blood pressure: systolic value and diastolic value
The blood pressure is given in numbers, for example, 120/80 mm Hg (millimeters of mercury), speaking 120 to 80.
- The systolic value (the first, higher, value, m example 120) results when the heart contracts and the blood presses into the arteries, i.e. during the pumping phase.
- Diastolic pressure (the second, lower value) occurs when the heart relaxes and the heart chambers refill with blood. Doctors speak of the recovery phase.
When is blood pressure too high?
Hypertension according to WHO values The specification for the definition of hypertension comes from the WHO, the World Health Organization. Currently (as of 2021), according to the WHO, a systolic value of at least 140 mm Hg and a diastolic blood pressure value equal to or more than 90 mm Hg are considered hypertonic – blood pressure above 140/90 mm Hg is therefore elevated. According to this definition, however, the increase in blood pressure must be permanent and not just temporary.
Experts: Limits for blood pressure values are arbitrary
Some scientists point out that the WHO hypertension values are set arbitrarily. Whether a blood pressure is too high or not can only be determined by taking an overall view of the patient’s state of health. Essentially, however, the WHO perspective has prevailed in conventional medicine.
Increased blood pressure is often not noticeable at first. The people affected often feel particularly fit and alert. Only very high blood pressure sometimes causes symptoms. Typical symptoms of hypertension are headache (often in the morning), dizziness, nausea, flushing of the face, nosebleeds, insomnia, fatigue, and ringing in the ears (tinnitus).
High Blood Pressure Crisis (hypertensive crisis)
Extremely high blood pressure values (over 230/130 mmHg) lead to a high blood pressure crisis. Then it becomes critical. High blood pressure crises cause shortness of breath and seizures, consciousness is clouded, in the worst case the affected people fall into a coma. There is also the risk of organ damage (such as acute heart failure, myocardial infarction or pulmonary edema) or brain damage (e.g. stroke and high-pressure encephalopathy), and rarely even the main artery tears (aortic dissection).
High Blood Pressure As A Risk Factor For Numerous Diseases
Longstanding hypertension can have serious consequences or complications. For example, high blood pressure is a recognized risk factor for atherosclerosis. High blood pressure in connection with being very overweight, diabetes or lipid metabolism disorders also significantly increases the risk of developing cardiovascular diseases. These diseases include:
Every second German now dies prematurely from cardiovascular disease.
In the majority of hypertensive patients, no clear cause of the increased blood pressure can be determined. Doctors call this high blood pressure “essential hypertension”. If another disease causes high blood pressure, it is called “secondary hypertension”. Increased blood pressure is also common during pregnancy (for example in pregnancy poisoning).
Risk Factors For Essential Hypertension
Essential hypertension can be triggered by a variety of factors. In addition to a genetic component, lifestyle also plays a major role. The following factors increase the risk of essential hypertension:
- Sedentary lifestyle
- high salt consumption
- excessive alcohol consumption
- Lipid metabolism disorders (e.g. increased cholesterol level)
- hereditary predisposition.
The diagnosis “essential hypertension” can only be made if other causes for the increased blood pressure have been ruled out.
Causes of Secondary Hypertension
Conditions that commonly cause high blood pressure include:
- Kidney disease (such as glomerulonephritis, cyst kidney, diabetic nephropathies, or narrowing of the renal arteries)
- Vascular diseases (such as arteriosclerosis or congenital malformations of the main artery)
- Hormonal disorders (such as Cushing’s syndrome, adrenal cortex disorders, pheochromocytoma, or diabetes)
- Sleep apnea syndrome.
Medicines such as hormonal contraceptives (birth control pills) or cortisone can also cause high blood pressure.
To avoid consequential damage and complications from high blood pressure, therapy for hypertension should begin as early as possible. High blood pressure is easily detected with a first and second blood pressure reading. If hypertension is suspected, blood pressure is measured 24 hours a day. In the further course blood tests, eye and urine tests, an electrocardiogram (EKG), and an ultrasound examination of the heart, as well as the neck and leg vessels, should be arranged.
In order to rule out other diseases as the cause of hypertension, imaging methods such as CT or MRI also help. Of course, the full spectrum of these examination methods is not always necessary for the diagnosis of high blood pressure.
So-called antihypertensive drugs are given for drug therapy of hypertension. There are a number of antihypertensive drugs that work differently. In Germany, more than 15 million men and women take medication for high blood pressure every day.
Medicines Containing Contaminated Valsartan
In 2018, one of these active ingredients made headlines in particular. Many drugs containing the active ingredient valsartan have been withdrawn from the market because they are contaminated with the substance N-nitrosodimethylamine (NDMA). Manufacturers who obtain their valsartan from the production of the Chinese supplier Zhejiang Tianyu are affected. Here is the list of affected valsartan preparations. Later, even the smallest amounts of NDMA were detected in another active ingredient from the group of sartans. Losartan from the Indian supplier Hetero Labs is affected. The drugs with this active ingredient were immediately withdrawn from the market.
In the meantime, the European Medicines Agency completed a risk assessment process for the sartans candesartan, irbesartan, losartan, olmesartan, and valsartan in summer 2019. The impurities can form during the production of sartans with a certain ring structure (tetrazole ring) under certain conditions and when certain solvents, reagents, and other starting materials are used. Additionally, it is possible that contaminants were present in some sartans because the manufacturers accidentally used contaminated equipment or reagents in the manufacturing process.
Do sartan users have to expect an increased risk of cancer?
NDMA is classified as likely to cause cancer in humans by the International Agency for Research on Cancer of the WHO and the EU. About 900,000 people in Germany take valsartan. Whether the long-term intake of valsartan contaminated with NDMA actually increases the risk of cancer cannot yet be reliably answered. Danish researchers published a study in September 2018 . It looked at data from more than 5,000 people who took valsartan between 2012 and 2017. These were men and women who had received either contaminated valsartan (approx. 11,900 patient-years) or uncontaminated valsartan (7,300 patient-years).
After analyzing the data, the scientists came to the conclusion that Valsartan contaminated with NDMA may not increase the general risk of cancer. But it is still too early for a reliable result. They also point out that in the group with NDMA contamination, a slightly higher rate of cases of colon cancer and uterine cancer was registered.
Sartans: What Should Patients Do Now?
Important for patients taking candesartan, irbesartan, losartan, olmesartan, and valsartan:
- Not all candesartan, irbesartan, losartan, olmesartan, and valsartan medicines are affected.
- Please do not interrupt the intake on your own.
- If you have any questions about your treatment, talk to your pharmacist, who can tell you whether your medicine is being recalled.
- If the medicine you are taking is affected, your doctor may prescribe a different medicine with an active ingredient that is not affected by the contamination.
- If you are in a clinical study with valsartan and have any questions, speak to the doctor in charge of the study.
- The sartans azilsartan, eprosartan, and telmisartan are not affected by the impurities due to their chemical structure.
Active ingredients against high blood pressure
The selection of the appropriate medication depends, among other things, on age, previous and concomitant illnesses as well as the response of blood pressure to the medication. The following antihypertensive drugs are given individually or in combination:
So-called diuretics such as thiazide diuretics, loop diuretics, potassium-sparing diuretics and aldosterone antagonists remove water from the body. This reduces the blood volume. When less blood flows through the veins, the pressure in the blood vessels decreases, and the blood pressure automatically drops. In addition, the heart is relieved and fluid accumulations in the tissue (edema) are flushed out.
Beta-blockers such as metoprolol, propranolol, or pindolol
These drugs block so-called beta-adrenaline receptors and thus reduce the effects of the stress hormone adrenaline and the neurotransmitter noradrenaline. As a result, blood pressure drops and the heart rate drops at rest.
Calcium channel blockers
Active ingredients of the dihydropyridine type such as amlodipine, lercanidipine, or nifedipine prevent the influx of calcium into heart muscle cells, cells of the stimulus-conduction system, and muscle cells of the blood vessels. Calcium is required for the tension of the muscle walls. If there is less calcium available, the muscle walls can constrict less, and muscle contraction decreases. The blood vessels in the heart and in the body widen and the blood pressure drops accordingly.
The antihypertensive ACE inhibitors such as captopril, enalapril, lisinopril, and ramipril act on the blood pressure regulation system (RAAS for short). They inhibit an enzyme (angiotensin-converting enzyme, ACE for short) that is required for the formation of angiotensin II from angiotensin I. Angiotensin II is the most powerful substance produced by the body. It directly increases blood pressure and indirectly inhibits the excretion of water. Without this conversion enzyme ACE, less angiotensin II is formed and the blood pressure increases less sharply.
AT-1 receptor antagonists and renin antagonists
AT-1 receptor antagonists are, for example, the sartans such as valsartan, losartan, and irbesartan: These drugs neutralize the blood pressure-increasing effect of angiotensin II (see above).
Renin antagonists such as aliskiren intervene in the blood pressure regulation system RAAS. You start at the very beginning of this cascade. This is how the hormone-like enzyme renin is bound. Renin is required for the conversion of angiotensinogen into angiotensin I. Less angiotensin I also means less angiotensin II. And the lower the angiotensin II concentration, the lower the increase in blood pressure.
2nd choice antihypertensive drugs
In addition to the drugs described, there are also second-choice active ingredients. This includes:
- Alpha-blockers (like prazosin and tamsulosin): These drugs affect the autonomic nervous system. In this nervous system – which we cannot deliberately influence – two nerve cords act: the sympathetic and the parasympathetic. The sympathetic nervous system is active when aroused and in dangerous situations, the parasympathetic nervous system in the resting state and the recovery phase. The sympathetic nervous system is stimulated via different receptors called alpha or beta receptors. Alpha-blockers block the alpha receptors. This reduces the stimulation of the sympathetic nervous system and lowers blood pressure.
- Potassium channel openers (such as minoxidil and diazoxide): Medicines in this group are used when other antihypertensive drugs are no longer working properly. They open the potassium channel and thus reduce the influx of potassium ions into the cells. As a result, the excitation of vascular muscle cells is reduced. The blood vessels relax and widen, and blood pressure drops.
- Alpha-2 agonists (such as clonidine): Alpha-2 agonists or alpha-2 sympathomimetics only attack alpha-2 receptors. In this way, they dampen the activity of the sympathetic nervous system and the blood pressure drops.
- NO donors (such as nitroglycerin and molsidomine): These organic nitrates reduce the tension in the vascular muscles. As a result, the larger arteries widen and blood pressure decreases.
Handle high blood pressure medication properly
If you have very high blood pressure, in particular, it is very helpful if you regularly check your blood pressure yourself. If you do not want to or cannot do this yourself, your pharmacist will be happy to assist you, for example. Of course, nursing services also take on this task. Ideally, you should keep a blood pressure diary in which you record the measured values for systolic and diastolic blood pressure on a daily basis. In the pharmacy, you can also get blood pressure monitors that automatically record the course of the blood pressure values.
Strictly observe the dosage regulations: In order for antihypertensive drugs to work reliably, it is necessary that you strictly adhere to the intake instructions. This applies to both the dosage and the time of day. Even if your blood pressure is normal, you may not change the dosage yourself or even discontinue your antihypertensive drug. Without the medication, blood pressure could rapidly rise again and sometimes cause life-threatening cardiac arrhythmias.
Disclose complete medication: It is not uncommon for drug interactions to lead to health-endangering complications. Antihypertensive drugs are often involved, if only because they are prescribed in such large numbers. It is imperative that you disclose to your doctor or physicians if you are taking any other medication.
Medicines do not eliminate the cause
As a rule, drugs do not eliminate the cause of hypertension, but only help to keep high blood pressure within healthy limits. In addition, antihypertensive drugs have a number of side effects and interactions. It is therefore recommended that the dose of the medication be kept as small as possible.
The best of all is not to let high blood pressure develop in the first place. You can contribute to this with simple rules of conduct, namely:
- Do not start or stop smoking in the first place.
- You should only drink alcohol in moderation.
- Watch your weight and lose weight if you are overweight.
- Make sure you have a balanced lifestyle with enough exercise and a fresh, healthy, and balanced diet.
- Limit your salt consumption.
- Treat or avoid lipid metabolism disorders.
- Avoid stress and high tension and learn relaxation techniques such as autogenic training, progressive muscle relaxation, yoga or tai chi.
- As a diabetic, you should ensure that your blood sugar level is well controlled.