Understanding high blood pressure
Blood pressure is a measure of the driving force in the arteries that propels the blood to the tissues and organs. Ideally, someone has a blood pressure that is high enough to drive blood to the organs, but not so high that it puts excessive load on the heart and blood vessels (10).
There is a key difference between chronic and malignant high blood pressure, and it is chronic blood pressure that is discussed most commonly. However, malignant hypertension is an emergency, as it is characterised by the rapid rise of blood pressure, and can lead to cardiac failure. Chronic hypertension is a slow rise in blood pressure over a long period of time, and frequently has no symptoms though sometimes it can cause headaches and other ‘heady’ sensations (14).
Blood pressure is measured in two numbers, one over the other (e.g. 118/76). The first number is a measure of the pressure in the arteries when the heart is in contraction, or beating. This is called the systolic pressure. The second number is a measure of the pressure in the arteries when the heart is not contracting, or between beats. This is called the diastolic pressure (2). Both the systolic and diastolic pressure inform the diagnosis of hypertension.
Chronic high blood pressure is a very common condition, with 1 in 4 people in England affected (2). The occurrence of hypertension increases with age, and half of people over 60 experience it (13). Socio-economic factors are significant in predicting outcomes as well, with people who are in more deprived areas 30% more likely to have high blood pressure than those who are in less deprived areas (2).
There are measures of blood pressure that are considered to be higher than normal. The blood pressure reading can be taken by a health provider, and high blood pressure should be assessed on the existence of other risk factors that the patient may have (13). There is however an increased acceptance and value of home blood pressure monitoring from health professionals. This is very useful in claiming back some autonomy over this condition, and makes it easier to introduce more self-management.
| Optimal blood pressure | 120/80 |
| Mild hypertension | 140/90 |
| Moderate hypertension | 160/100 |
| Severe hypertension | 180/110 |
Generally, 140/90mmHg or higher is considered to be hypertension. Or if you are over the age of 80 then 150/90mmHg or higher is considered high blood pressure. The ideal blood pressure is considered between 90/60mmHg and 120/80mmHg (17).
The types of medication that are used to reduce high blood pressure are called anti-hypertensive drugs and there are several categories that are defined by their mechanisms of action. These drugs are selected on the bases of age, co-morbidities, and ethnic background as well as cost. Frequently, medications are combined (13).
- Thiazide and other diuretics: These drugs inhibit sodium reabsorption in the kidneys, and a low dose is used for high blood pressure management (7).
- ACE inhibitors: These drugs inhibit the conversion of angiotensin I to angiotensin II. Their side effects include a cough, rash, and kidney dysfunction (13). They are frequently the type of medication initially prescribed for patients with high blood pressure, however they are not appropriate for pregnancy (7).
- Angiotensin receptor blockers: These have similar effects to ACE inhibitors. Combining them with ACE inhibitors for controlling blood pressure is not recommended (7).
- Calcium channel antagonists: These are considered well-tolerated and especially appropriate for patient over 55 who do not have Type 2 diabetes (7). Their side effects include flushing, palpitations, and fluid retention (13).
- Beta-blockers: These drugs block receptors that are involved in vasodilation and bronchodilation. They are no longer routinely used as a first line therapy for hypertension (14).
- Beta and alpha-adrenoreceptor antagonists: These can be used when beta-blockers are not sufficiently effective. Labetalol is used for malignant hypertension (15).
- Vasodilators: There are several drugs that act directly on the smooth muscle of the blood vessels. The side effects can be postural hypotension (dizzy on standing), headache, irregular or fast heart beat, and fluid retention (13).
How does blood pressure work?
Chronic high blood pressure may be classified as primary (or essential) or secondary. Secondary hypertension occurs when there is a clear cause of high blood pressure, such as kidney disease, endocrine disease, prescription medication, advanced atherosclerosis, or pre-eclampsia (10,11). Secondary hypertension accounts for approximately 5% of cases of chronic high blood pressure (13).
Primary, or essential, hypertension accounts for approximately 95% of cases of high blood pressure. This means that the specific cause of the condition is unclear. However, there are many environmental risk factors that may contribute to its development (13). These include exposure to chronic stress, obesity, a lack of physical activity and high alcohol or salt intake.
Understanding the root
The manner in which chronic primary high blood pressure develops is poorly understood, but is assessed in relation to the presence of risk factors. The modifiable risk factors are the types of risk factors that can be changed, such as high salt intake, high alcohol consumption, obesity, and a lack of exercise (13). Often, a high salt intake is due to high consumption of refined carbohydrates, which are also linked to co-morbidities such as insulin resistance. The link between chronic stress and high blood pressure is an area of study that is underway, but stress may also be a risk factor (4).
Other factors are non-modifiable, meaning that they cannot be changed. These are age, sex, and genetics. As people age, their blood pressure tends to rise. Females tend to have lower blood pressure than males until the age of 65. A family history of high blood pressure may increase risk (2).
A diagnosis of high blood pressure requires accurate blood pressure measurements, often over a period of time as blood pressure changes throughout the day. These readings are to be taken while assessing risk factors, and establishing whether there is an identifiable cause. Any damage that may have been caused to organs due to increased blood pressure must also be assessed, before determining a therapeutic route (13).
There are several complications of chronic high blood pressure, which treatment seeks to address. Because of the internal pressure of the arteries and blood vessels, the heart must work harder and damage may occur to the vessel wall. This may lead to stroke, coronary artery disease, heart failure, and atherosclerosis. Damage may also occur to vascular organs, which may include kidney failure (10,13).
Signs and symptoms
Chronic high blood pressure is most often asymptomatic (13). However, there are some symptoms that may indicate high blood pressure. These symptoms may indicate another pathology, so it is important to seek the advice a medical professional if any of these symptoms are present.
- Shortness of breath
- Blurred vision
- Nosebleeds
- Chest pain
- Dizziness (3)
Herbal solutions
- Garlic (Allium sativum) has been shown to reduce high blood pressure, likely due to one of its active constituents, allicin (8).
- Celery seed (Apium graveolens) is a known herbal diuretic. One study found that a powder of the seeds lowered blood pressure (11).
- Gotu kola (Centella asiatica) helps support tissues such as blood vessels, and moderate stress responses.
- Hawthorn (Crataegus spp.) has a long history of supporting the heart and circulatory system.
- Ginkgo (Ginkgo biloba) is used to support circulation, especially cerebral and peripheral circulation. Its effects on hypertension are inconclusive (15).
- Hibiscus (Hibiscus sabdariffa) has been studied extensively for its ability to lower blood pressure, with positive results in lowering both systolic and diastolic blood pressure (9).
- Tulsi (Ocimum tenuiflorum) is an Ayurvedic herb that is also known in the Western tradition for its ability to assist in stress responses. It may aid in lowering blood pressure.
- Olive leaf (Olea europea) acts as a vasodilator and may help in cases of hypertension.
- Rauwolfia (Rauwolfia serpentina) has a long history of use in India, with evidence of lowering blood pressure. The toxicity of this herb has been debated, and it is endangered so should not be used (5).
- Limeflower (Tilia spp.) is a relaxing herb that also relaxes the blood vessels.
- Bilberry (Vaccinium myrtillus) is supportive of the circulatory system, especially peripheral circulation.
- Mistletoe (Viscum album) leaves are used to reduce blood pressure as it shows some vasodilation activity (12). Note that the berries are toxic, and should not be consumed.
- Ginger (Zingiber officinale) supports peripheral circulation.
A herbalist will take a full case history to determine the primary factors contributing to high blood pressure for the patient and make a holistic and personalised formula. For example, if chronic high stress is a dominant piece of the patient’s picture, for example, adaptogens and nervines will feature strongly in the formula (such as gotu kola or limeflower).
Holistic solutions
Mild hypertension may be alleviated by dietary and lifestyle changes. Additionally, the dose or the number of anti-hypertensive drugs may be reduced (13). All treatment for high blood pressure should be alongside lifestyle recommendations (7).
Restrict salt intake
Salt is involved in several processes that may contribute to blood pressure control. A lower salt diet has been shown to improve blood pressure parameters in those with hypertension (1).
The Mediterranean or DASH Diet
The Mediterranean Diet is based on the lifestyle and food choices of those living in the Mediterranean. The diet has a high amount of fruit, vegetables, pulses, monounsaturated and polyunsaturated fat, as well as low consumption of red meat and alcohol. The DASH Diet is considered the diet of choice for those diagnosed with hypertension. The diet increases intake of fruit and vegetables, low-fat dairy products, and reduces intake of saturated fats. Both have been found to have a favourable effect on blood pressure (6).
Regular exercise
Moderate aerobic exercise performed for 30 minutes a day, four days per week can help reduce blood pressure (9). Those with a higher fitness level are less likely to develop hypertension. Weight loss in cases of obesity is also correlated to a reduction in blood pressure (5).
Limit alcohol consumption
Alcohol intake has a direct correlation to blood pressure, and excess alcohol intake may be responsible for up to 30% of hypertension cases (6). A maximum of one drink per day is recommended for those over 65 years old, and a maximum of two a day for those under 65 (9). However, non-drinkers have been shown to have lower blood pressure than moderate drinkers, so a reduction in alcohol intake is always recommended for those with hypertension (6).
Quit smoking
The nicotine found in tobacco activates the sympathetic nervous system. This raises blood pressure (10).
Manage stress
Stress increases hormones like cortisol that in turn increase blood pressure. Although studies have conflicting results with how much stress is correlated with chronically high blood pressure, introducing healthy management strategies may help manage blood pressure through reducing unhealthy coping mechanisms such as drinking or smoking (6). Other stress management techniques, such as meditation, breathwork practices, and movement such as yoga or qigong may also be employed to benefit. Breathing practices in particular have shown evidence to help lower blood pressure (16). Integrating holistic practices can be a powerful way to get to the root of an issue and prevent it occurring as frequently.
References
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- Health matters: combating high blood pressure. GOV.UK. https://www.gov.uk/government/publications/health-matters-combating-high-blood-pressure/health-matters-combating-high-blood-pressure. Published 2021. Accessed November 29, 2021.
- High blood pressure – symptoms and treatment. Bhf.org.uk. https://www.bhf.org.uk/informationsupport/risk-factors/high-blood-pressure/symptoms-and-treatment. Published 2021. Accessed November 29, 2021.
- Liu M, Li N, Li W, Khan H. Association between psychosocial stress and hypertension: a systematic review and meta-analysis. Neurol Res. 2017;39(6):573-580. doi:10.1080/01616412.2017.131790
- Lobay D. Rauwolfia in the Treatment of Hypertension. Integr Med (Encinitas). 2015;14(3):40-46.
- Mahmood S, Shah K, Khan T et al. Non-pharmacological management of hypertension: in the light of current research. Irish Journal of Medical Science (1971 -). 2018;188(2):437-452. doi:10.1007/s11845-018-1889-8
- NICE. BNF. https://www.nice.org.uk. Published 2021. Accessed November 30, 2021.
- Ried K, Frank O, Stocks N, Fakler P, Sullivan T. Effect of garlic on blood pressure: A systematic review and meta-analysis. BMC Cardiovasc Disord. 2008;8(1). doi:10.1186/1471-2261-8-13
- Serban C, Sahebkar A, Ursoniu S, Andrica F, Banach M. Effect of sour tea (Hibiscus sabdariffa L.) on arterial hypertension. J Hypertens. 2015;33(6):1119-1127. doi:10.1097/hjh.0000000000000585
- Sherwood L. Human Physiology. Toronto: Cengage; 2018.
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- Tenorio F, del Valle L, González A, Pastelín G. Vasodilator activity of the aqueous extract of Viscum album. Fitoterapia. 2005;76(2):204-209. doi:10.1016/j.fitote.2004.12.013
- Walker B, Colledge N, Penman I, Ralston S. Davidson’s Principles And Practice Of Medicine. London: Elsevier Saunders; 2014.
- Wilson K, Waugh A. Ross And Wilson Anatomy And Physiology In Health And Illness. New York: Churchill Livingstone; 2010.
- Xiong X, Liu W, Yang X et al. Ginkgo biloba extract for essential hypertension: A systemic review. Phytomedicine. 2014;21(10):1131-1136. doi:10.1016/j.phymed.2014.04.024
- Mourya, M. and Mahajan, A., 2009. Effect of Slow- and Fast-Breathing Exercises on Autonomic Functions in Patients with Essential Hypertension | The Journal of Alternative and Complementary Medicine. [online] The Journal of Alternative and Complementary Medicine. Available at: <https://www.liebertpub.com/doi/abs/10.1089/acm.2008.0609> [Accessed 16 December 2021].
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