According to Naish and Court (2014), hypertension also known as high blood pressure (HBP), is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. Blood pressure is the force exerted by circulating blood against the walls of the body’s arteries, the major blood vessels in the body. Hypertension is when blood pressure is too high. Blood pressure is written as two numbers. The first (systolic) number represents the pressure in blood vessels when the heart contracts or beats. The second (diastolic) number represents the pressure in the vessels when the heart rests between beats. Hypertension is diagnosed if, when it is measured on two different days, the systolic blood pressure readings on both days is ≥140 mmHg and/or the diastolic blood pressure readings on both days is ≥90 mmHg [World Health Organisation (WHO), 2019]
Mayo Clinic (2021) describes high blood pressure (hypertension) is a common condition in which the long-term force of the blood against your artery walls is high enough that it may eventually cause health problems, such as heart disease. It is determined both by the amount of blood your heart pumps and the amount of resistance to blood flow in your arteries. The more blood your heart pumps and the narrower your arteries, the higher your blood pressure. You can have high blood pressure for years without any symptoms. Uncontrolled high blood pressure increases your risk of serious health problems, including heart attack and stroke.
Prevalence of Hypertension in Nigeria
Globally, an estimated 26% of the world’s population (972 million people) has hypertension, and the prevalence is expected to increase to 29% by 2025, driven largely by increases in economically developing nations (Kearney, Whelton, Reynolds, Muntner, Whelton & He, 2005). The high prevalence of hypertension exacts a tremendous public health burden. As a primary contributor to heart disease and stroke, the first and third leading causes of death worldwide, respectively, high blood pressure was the top modifiable risk factor for disability adjusted life-years lost worldwide in 2013 [Global Burden of Disease (GBD), 2013]
A study carried out by Odili, Chori, Danladi, Nwakile, Okoye, Abdullah, et al. (2020) revealed that 38% of adult Nigerians aged 18 years and above were hypertensive. Out of the hypertensive subjects, 60% were aware of their status, one-third was receiving treatment and 12% had their blood pressure under control. Prevalence of hypertension ranged from 20.9% in the North-Central to 52.8% in the South-East region. The study also noted that hypertension was as common in the rural as in the urban areas; however, the urban dwellers were more aware of and received treatment for the condition more than their rural counterparts.
Causes (Contributory Factors) of Hypertension (High Blood Pressure)
Hypertension can be grouped into two major categories (primary and secondary hypertension) which are as a result of what is causing the hypertension in an individual.
Primary hypertension results from a complex interaction of genes and environmental factors. Numerous common genetic variants with small effects on blood pressure have been identified as well as some rare genetic variants with large effects on blood pressure. Also, genome-wide association studies (GWAS) have identified 35 genetic loci related to blood pressure; 12 of these genetic loci influencing blood pressure were newly found. Sentinel SNP for each new genetic locus identified has shown an association with DNA methylation at multiple nearby CpG sites. These sentinels SNP are located within genes related to vascular smooth muscle and renal function. DNA methylation might affect in some way linking common genetic variation to multiple phenotypes even though mechanisms underlying these associations are not understood. Single variant test performed in this study for the 35 sentinel SNP (known and new) showed that genetic variants singly or in aggregate contribute to risk of clinical phenotypes related to high blood pressure (Kato, Loh, Takeuchi, Verweij, Wang, Zhang, et al., 2015).
Blood pressure rises with aging when associated with a western diet and lifestyle and the risk of becoming hypertensive in later life is significant. Several environmental factors influence blood pressure. High salt intake raises the blood pressure in salt sensitive individuals; lack of exercise, central obesity can play a role in individual cases. The possible roles of other factors such as caffeine consumption and vitamin D deficiency are less clear. Insulin resistance, which is common in obesity and is a component of syndrome X (or the metabolic syndrome), also contributes to hypertension (Sorof & Daniels, 2002).
Events in early life, such as low birth weight, maternal smoking, and lack of breastfeeding may be risk factors for adult essential hypertension, although the mechanisms linking these exposures to adult hypertension remain unclear. An increased rate of high blood uric acid has been found in untreated people with hypertension in comparison with people with normal blood pressure, although it is uncertain whether the former plays a causal role or is subsidiary to poor kidney function. Average blood pressure may be higher in the winter than in the summer. Periodontal disease is also associated with high blood pressure (Muñoz, Suvan, Buti, Czesnikiewicz-Guzik, Barbosa, Orlandi, et al., 2020).
Secondary hypertension results from an identifiable cause. Kidney disease is the most common secondary cause of hypertension. Hypertension can also be caused by endocrine conditions, such as Cushing’s syndrome, hyperthyroidism, hypothyroidism, acromegaly, Conn’s syndrome or hyperaldosteronism, renal artery stenosis (from atherosclerosis or fibromuscular dysplasia), hyperparathyroidism, and pheochromocytoma. Other causes of secondary hypertension include obesity, sleep apnea, pregnancy, coarctation of the aorta, excessive eating of liquorice, excessive drinking of alcohol, certain prescription medicines, herbal remedies, and stimulants such as cocaine and methamphetamine. Arsenic exposure through drinking water has been shown to correlate with elevated blood pressure. Depression was also linked to hypertension. Loneliness is also a risk factor (Hawkley & Cacioppo, 2010).
Signs and Symptoms of Hypertension (High Blood Pressure)
According to Beckerman (2020), one of the most dangerous things about hypertension — or high blood pressure — is that you may not know you have it. In fact, nearly one-third of people who have high blood pressure don’t know it. That’s because high blood pressure doesn’t have any symptoms unless it’s very severe. The best way to know if your blood pressure is high is through regular checkups.
He however added that if your blood pressure is extremely high, there may be certain symptoms to look out for, including:
- Severe headaches
- Fatigue or confusion
- Vision problems
- Chest pain
- Difficulty breathing
- Irregular heartbeat
- Blood in the urine
- Pounding in your chest, neck, or ears
People sometimes feel that other symptoms may be related to high blood pressure, but they may not be:
- Trouble sleeping
- Facial flushing
- Blood spots in eyes
Risk Factors Associated with Hypertension (High Blood Pressure)
University of California San Francisco Health (2019) highlighted the most common risk factors for high blood pressure to include:
- Being Overweight or Obese: The more you weigh the more blood flow you need to supply oxygen and nutrients to your tissues. As the volume of blood circulated through your blood vessels increases, so does the pressure inside your arteries.
- Too Much Salt (Sodium) in Your Diet: Too much sodium in your diet can cause your body to retain fluid, and also causes the arteries in your body to constrict. Both factors increase blood pressure.
- Too Little Potassium in Your Diet: Potassium helps balance the amount of sodium in your cells. Potassium causes the smooth muscle cells in your arteries to relax, which lowers blood pressure.
- Not Being Physically Active: Exercise increases blood flow through all arteries of the body, which leads to release of natural hormones and cytokines that relax blood vessels, which in turn lowers blood pressure. Lack of physical activity also increases the risk of being overweight.
- Drinking Too Much Alcohol: Having more than two drinks per day can cause hypertension, probably by activating your adrenergic nervous system, causing constriction of blood vessels and simultaneous increase in blood flow and heart rate.
- Stress: High levels of stress can lead to a temporary, but dramatic, increase in blood pressure. If you try to relax by eating more, using tobacco or drinking alcohol, you may only exacerbate problems with high blood pressure. Relaxation and meditation techniques effectively lower blood pressure.
- Non-steroidal Anti-inflammatory Drugs (NSAIDs): Ibuprofen (Advil, Motrin, Ibuprofen) can cause marked worsening of existing hypertension or development of new high blood pressure. It can also cause damage to the kidneys, worsening of heart failure, and even heart attack or stroke. Ibuprofen is a member of the class of drugs called NSAIDs, which includes naproxen (Aleve, Naprosyn and Anaprox), sulindac (Clinoril), diclofenac (Voltaren), piroxicam (Feldene), indomethacin (Indocin), Mobic, Lodine and celecoxib (Celebrex).
- Cough and Cold Medications (Sudafed and Other Brands that Contain Pseudoephedrine and Phenylephrine): Cough and cold medicines frequently contain decongestants such as pseudoephedrine and phenylephrine. These medications cause your blood pressure and heart rate to rise, by constricting all your arteries, not just those in your nose.
- Certain Chronic Conditions: Certain chronic conditions, including diabetes, kidney disease and sleep apnea, also may increase your risk of high blood pressure.
- A Diet Low in vitamin D: It’s uncertain if having too little vitamin D in your diet can lead to high blood pressure. Researchers think that vitamin D may affect an enzyme produced by your kidneys that affects your blood pressure. More studies are necessary to determine vitamin D’s exact role in high blood pressure. However, talk to your doctor about whether you may benefit from taking a vitamin D supplement.
Management and Treatment of Hypertension (High Blood Pressure)
According to Law, Wald and Morris (2003), reduction of the blood pressure by 5 mmHg can decrease the risk of stroke by 34%, of ischemic heart disease by 21%, and reduce the likelihood of dementia, heart failure, and mortality from cardiovascular disease. Below are some of the most notable measures in the management and treatment of hypertension:
- Target Blood Pressure
- Lifestyle Modifications
Target Blood Pressure
Arguedas, Leiva and Wright (2020) highlighted guidelines regarding how low the blood pressure target should be when a person is treated for hypertension. They recommend a target below the range 140–160 / 90–100 mmHg for the general population and the target of 150/90 mmHg for those over 60 years of age. For people who have never experienced cardiovascular disease who are at a 10-year risk of cardiovascular disease of less than 10%, the 2017 American Heart Association guidelines recommend medications if the systolic blood pressure is >140 mmHg or if the diastolic BP is >90 mmHg. For people who have experienced cardiovascular disease or those who are at a 10-year risk of cardiovascular disease of greater than 10%, it recommends medications if the systolic blood pressure is >130 mmHg or if the diastolic BP is >80 mmHg (Whelton et al., 2018).
The first line of treatment for hypertension is lifestyle changes, including dietary changes, physical exercise, and weight loss. If hypertension is high enough to justify immediate use of medications, lifestyle changes are still recommended in conjunction with medication. Dietary changes shown to reduce blood pressure include diets with low sodium, the DASH diet (Dietary Approaches to Stop Hypertension), plant-based diets and green tea consumption. Increasing dietary potassium has a potential benefit for lowering the risk of hypertension. However, people who take certain antihypertensive medications (such as ACE-inhibitors or ARBs) should not take potassium supplements or potassium-enriched salts due to the risk of high levels of potassium. Physical exercise regimens which are shown to reduce blood pressure include isometric resistance exercise, aerobic exercise, resistance exercise, and device-guided breathing. Stress reduction techniques such as biofeedback or transcendental meditation may be considered as an add-on to other treatments to reduce hypertension, but do not have evidence for preventing cardiovascular disease on their own (Brook et al., 2013).
Several classes of medications, collectively referred to as antihypertensive medications, are available for treating hypertension. First-line medications for hypertension include thiazide-diuretics, calcium channel blockers, angiotensin converting enzyme inhibitors (ACE inhibitors), and angiotensin receptor blockers (ARBs). These medications may be used alone or in combination (ACE inhibitors and ARBs are not recommended for use in combination); the latter option may serve to minimize counter-regulatory mechanisms that act to restore blood pressure values to pre-treatment levels. Most people require more than one medication to control their hypertension. Medications for blood pressure control should be implemented by a stepped care approach when target levels are not reached (Glynn, Murphy, Smith, Schroeder & Fahey, 2010).
Measures to Prevent Hypertension (High Blood Pressure)
According to Centre for Disease Control and Prevention (CDC) (2020), practicing healthy living habits, like being physically active, helps to prevent high blood pressure. By living a healthy lifestyle, you can help keep your blood pressure in a healthy range. Preventing high blood pressure, which is also called hypertension, can lower your risk for heart disease and stroke. Practice the following healthy living habits:
- Eat a Healthy Diet
- Keep Yourself at a Healthy Weight
- Be Physically Active
- Do Not Smoke
- Limit How Much Alcohol You Drink
- Get Enough Sleep
Eat a Healthy Diet
Choose healthy meal and snack options to help you avoid high blood pressure and its complications. Be sure to eat plenty of fresh fruits and vegetables. Talk with your health care team about eating a variety of foods rich in potassium, fiber, and protein and lower in salt (sodium) and saturated fat. For many people, making these healthy changes can help keep blood pressure low and protect against heart disease and stroke. The DASH (Dietary Approaches to Stop Hypertension) eating plan is a healthy diet plan with a proven record of helping people to lower their blood pressure.
Keep Yourself at a Healthy Weight
Having overweight or obesity increases your risk for high blood pressure. To determine whether your weight is in a healthy range, doctors often calculate your body mass index (BMI). Talk with your health care team about ways to reach a healthy weight, including choosing healthy foods and getting regular physical activity.
Be Physically Active
Physical activity can help keep you at a healthy weight and lower your blood pressure. The Physical Activity Guidelines for Americans recommends that adults get at least 2 hours and 30 minutes of moderate-intensity exercise, such as brisk walking or bicycling, every week. That’s about 30 minutes a day, 5 days a week. Children and adolescents should get 1 hour of physical activity every day.
Do Not Smoke
Smoking raises your blood pressure and puts you at higher risk for heart attack and stroke. If you do not smoke, do not start. If you do smoke, quitting will lower your risk for heart disease.
Limit How Much Alcohol You Drink
Do not drink too much alcohol, which can raise your blood pressure. Men should have no more than 2 alcoholic drinks per day, and women should have no more than 1 alcoholic drink per day.
Get Enough Sleep
Getting enough sleep is important to your overall health, and enough sleep is part of keeping your heart and blood vessels healthy. Not getting enough sleep on a regular basis is linked to an increased risk of heart disease, high blood pressure, and stroke.
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