Causes of High Blood Pressure
There are two possible types of high blood pressure:
- primary hypertension (common)
- secondary hypertension (rare)
Secondary hypertension is usually a consequence of other medical conditions.
Blood pressure
The human heart cycle always has two phases: systole (pumping phase) and diastole (filling phase). This produces a systolic and a diastolic pressure in the blood vessels. When the heart contracts, the systolic (higher) pressure occurs. When the heart relaxes, the diastolic (lower) pressure occurs. Blood pressure is also influenced by the large elastic arteries close to the heart and the smaller resistance vessels (organ arteries). Pressure that results from increased heart output responds in healthy people to the body's needs, ensuring adequate blood flow.
Blood pressure isn't constant and varies depending on the time of day. For example, it falls during sleep and is higher during the day (see Blood pressure during the day). Blood pressure also often increases with age. Physical activity raises blood pressure. For patients with high blood pressure this can be dangerous, because exercise (especially strength training) can cause spikes that might, in some cases, be lifethreatening. Endurance sports like running, cycling, or crosscountry skiing have the opposite effect and can lower blood pressure in the long term.
Causes of high blood pressure
Primary high blood pressure, which occurs without a specific underlying disease, is promoted by certain risk factors, some of which can be influenced by lifestyle. These include
- overweight and abdominal obesity
- Smoking
- physical inactivity
- excessive alcohol
- chronic stress
- Table salt (partly)
Risk factors that cannot be changed include, among others
- age
- sex
- genetic factors
If there is already a predisposition to high blood pressure, the modifiable risk factors have an even easier time contributing to the development of high blood pressure.
Risk factors for developing primary hypertension
Overweight and abdominal obesity
Being overweight (BMI from BMI 25, obesity from 30) can promote high blood pressure because it increases the workload on the heart. But not only excess weight as such is a risk factor. Because blood pressure often rises as a result of insulin resistance associated with obesity, the distribution of body fat also matters. Pay particular attention to the belly and waist, because abdominal fat contributes to muscle, fat, and liver cells responding less well to insulin. The body then needs more insulin, increasing the risk of type 2 diabetes. When overweight, hypertension, and diabetes mellitus occur together, this is called the metabolic syndrome.
Nicotine doesn't just damage the coronary arteries and leg arteries. It causes narrowing of all blood vessels. The harmful substances (especially free radicals) destroy the vessel lining's (endothelium) ability to dilate. This encourages atherosclerosis (hardening of the arteries). The resulting worsening of the blood's flow properties thus leads to a persistent rise in blood pressure.
Lack of exercise generally weakens the body. The heart cannot work efficiently. Even with small exertion it runs at high speed. Physical activity can lower both systolic (upper reading) and diastolic (lower reading) blood pressure in patients with high blood pressure over the long term.
Alcohol in larger amounts can temporarily raise blood pressure. With longterm heavy consumption it can lead to chronic high blood pressure. Alcohol harms not only the heart and circulation and thus blood pressure, but also the brain and liver.
Stress that isn't balanced or overcome over a long time can raise blood pressure via the autonomic nervous system. The part called the sympathetic nervous system controls vital functions like blood pressure and circulation. It allows quick increases in performance, which is why it plays a key role in the response to stress. The parasympathetic nervous system sends calming signals for relaxation and stress recovery. Unmanaged stress can also lead to sleep problems, which also negatively affect blood pressure. With a high stress level the body is under constant tension and cannot recover.
Intake of sodium chloride, i.e. table or cooking salt, makes the smaller arteries involved in blood pressure regulation more sensitive to circulating hormones. This can lead to an increase in blood pressure. The DGE (German Nutrition Society) recommends a maximum daily salt intake of 6 grams, which is about one teaspoon. If high blood pressure is already being treated, too much salt can make treatment more difficult, and reducing salt can help.
Causes of secondary hypertension
Causes of secondary hypertension are usually due to an underlying disease. These often include metabolic disorders, kidney disease, or vascular disease. A congenital narrowing of the main artery (aorta) can also be a cause. Hormonal medications (for example the birth control pill) or rheumatism drugs, as well as certain illegal drugs (for example amphetamines, cocaine), are also possible causes of high blood pressure.
A special type of secondary hypertension: pregnancy-related high blood pressure
Pregnancy-related high blood pressure is a special form of secondary hypertension. It is not caused by another disease. Rather, pregnancy and the changes associated with it trigger the high blood pressure. About six to eight percent of expectant mothers are affected by this form of hypertension. The risk is significantly higher in women aged 40 and over or in multiple pregnancies. The causes are socalled hypertensive disorders of pregnancy (for example preeclampsia, eclampsia, HELLP syndrome), which can develop quickly and endanger both mother and child. That's why blood pressure is monitored regularly during pregnancy.
Sources:
This article comes from BloodPressureDB – the leading app since 2011 that helps hundreds of thousands monitor their blood pressure every day.
Our content is based on carefully researched, evidence-based data and is continuously updated (as of 01/2024).
Author Sabine Croci is a qualified medical assistant with many years of experience in internal medicine and cardiology practices as well as in outpatient care, and has led BloodPressureDB's specialist editorial team since 2015. Thanks to her extensive additional qualifications as a paramedic, first responder and in various therapy and emergency areas, she provides solid, practical and reliably reviewed information.
Author Sabine Croci is a qualified medical assistant with many years of experience in internal medicine and cardiology practices as well as in outpatient care, and has led BloodPressureDB's specialist editorial team since 2015. Thanks to her extensive additional qualifications as a paramedic, first responder and in various therapy and emergency areas, she provides solid, practical and reliably reviewed information.
