HYPERTENSION: THE BASICS
Introduction: Understanding the Basics
The heart pumps blood through the arteries, supplying oxygen and nutrients to the organs and muscles of the body. With each heart beat, as blood is pumped through the vessels, it exerts some pressure on the walls of the artery. This pressure is what constitutes your blood pressure. Blood pressure vary among individuals, fluctuates through out the day, specifically in response to activities. It is referred to as high blood pressure when the pressure becomes persistently high. Blood pressure affects the opening and narrowing of the arteries, when it is high, the muscles in the walls of the arteries thicken, narrowing the space for blood flow which further increases blood pressure. In hypertension, the heart has to work hard to pump blood into high pressure vessels. If hypertension is not controlled, it may result in several complications such as kidney failure, blindness, heart failure, enlarged heart that is too weak to pump blood, stroke, aneurysms (bulge in blood vessels) that may burst and leak into the brain.
Epidemiology
Classification
This is based on recommendations by the JNC (Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure)
- Normal : systolic BP <120 mm Hg or diastolic BP <80 mm Hg
- Pre-hypertension: systolic BP 120-139 mm Hg or diastolic BP 80-89 mm Hg
- Stage 1: Systolic BP 140-159 mm Hg or diastolic 90-99 mm Hg
- Stage 2: Systolic BP 160 mm Hg or diastolic BP ≥100 mm Hg
Signs and Symptoms
High blood pressure is referred to as a silent killer as most people with the condition may not experience any symptom. In few cases, the individual may experience vague, non specific symptoms such as:
- Headaches (mostly in the back of the head)
- Shortness of breath
- Heart palpitations
- Nose bleeds
These symptoms are not specific to hypertension so should never be relied upon to diagnose high blood pressure. It is advised to check your blood pressure regularly, as it can change at any time, most especially if you are at risk of developing high blood pressure.
Types and Causes
There are basically two types depending on the cause
- Essential hypertension: Cause is mostly unknown. It is thought to be as a result of interaction between genetics (runs in the family) and environmental factors. Several risk factors (smoking, diabetes, obesity, stress, high salt/high fat diet, age) may dispose an individual to develop high blood pressure. It is more common in men than women and, in people of African descent than Caucasians till about 44 years after which the prevalence becomes similar across both ethnicity (4). Essential hypertension is responsible for 90-95% of cases of hypertension.
- Secondary hypertension: In this case, there is an identifiable cause of hypertension. Known secondary causes of high blood pressure include: Kidney diseases, cancers ( when they produce certain substances that increases blood pressure), estrogen based birth control pills, medications, cocaine, nicotine in cigarettes, thyroid disease.
Diagnosis: Monitoring your Blood Pressure
Blood pressure values are recorded as two numbers, the first one is referred to as systolic BP while the second number is the value for diastolic BP, for example 120/80 mm Hg. The systolic BP value represents the pressure in your blood vessels when your heart beats, and diastolic BP value is the pressure in the blood vessels when the heart is resting between beats.
It is important to check your blood pressure with your doctor regularly. Some drugstores offer high blood pressure check, so that may be a more convenient option for you. For the diagnosis of high BP to be made, your BP readings must be consistently high when taken at least on two separate occasions.
There are several blood pressure monitors available: electronic/automatic or mercury sphygmomanometer. The american heart association recommends using digital BP monitor at home. It is easy to use, requires less skills and produces reliable results.
It is also important to ensure you are getting accurate results, so, after acquiring your BP monitor, it is recommended that you take it along to your next visit to the doctor. Your healthcare provider will show you how to use it correctly for accurate results. Note that, battery malfunction may also give inaccurate results, therefore always check the batteries.
It is recommended to always keep a blood pressure journal. BP changes from time to time, so it becomes important to record the values in order to understand the overall trend of your BP and what your baseline looks like. Keeping a journal may help you and your doctor come up with a treatment plan to optimally manage your high blood pressure.
How to choose a home BP monitor
- The American Heart Association recommends an automatic, cuff style, upper arm BP monitor.
- Buy an automated BP monitor that has been validated. Pharmacists and your healthcare provider would be able to suggest a good one.
- Make sure it is your cuff size. BP cuffs come in different sizes, using the wrong cuff will give you inaccurate values.
Note: Finger or wrist monitors are not recommended as validated BP monitors.
Risk Factors
- Family history: You are likely to develop high BP if either of your parents or any of your siblings have hypertension.
- Age: Risk of developing high BP increases with age. It is common in people above age 35, mostly males. Women are more likely, than men, to develop hypertension after the age of 65.
- Ethnicity/Race: People of African descent tend to develop high blood pressure at an earlier age than non Africans.
- Obesity: Increase in body mass increases the amount of work the heart has to do, inorder to pump blood into the vessels and the pressure exerted by blood in the vessels.
- Smoking: tobacco use will increase your BP. It releases substances that injure and damage the blood vessels, resulting in narrow arteries.
- Drinking alcohol in excess: Studies have shown that heavy alcohol consumption can cause damage to the heart. Recommended quantity of drink per day, 1 drink/day for females and 2 drinks/day in males. Note that: 5 ounces of wine or 12 ounces of beer.
- Sedentary lifestyle
- High salt diet: High salt diet leads to water retention. When you have too much water in body, your BP will increase and the heart will have to work harder to pump the high fluid volume.
- High fat diet: Diet high in fat is likely to deposit, damage and block the vessels.
- Caffeine: consuming high caffeine foods, caffeinated drinks, tea, coffee may all lead to hypertension.
- Birth control pills
- Stress and sleep deprivation: Consistently leading a stressful life is likely to increase your chances of high blood pressure. Stress makes your body release substances, including hormones, that narrow the blood vessels, increase the heart rate and consequently increase your BP. Chronic stress results in repeated blood pressure elevation that eventually may lead to hypertension. Stressors in your life may be in the form of job stress, emotional, grief and bereavement, social anxiety, white-coat hypertension. (5) Sleeping for less than 7-8 hours per night may also increase your risk of hypertension.
- People with conditions such as pre-hypertension, diabetes, obstructive sleep apnea are at increased risk of developing high blood pressure.
Steps to Keeping your BP Under Control
- Diet: The DASH (Dietary Approaches to Stop Hypertension) and Mediterranean diets are the most commonly recommended diets for the control and prevention of high BP. The DASH diet is based on NIH (National Institute of Health) studies to investigate the effect of diet on blood pressure. The DASH diet consists of fruits, vegetables, low-fat dairy, whole grains, low fat diet, low salt, nuts, no added sugars, and substituting red meats (beef, veal, pork, lamb, and mutton) with poultry and fish. Mediterranean diet is a heart healthy eating plan that consists mostly of plant based foods: fruits and vegetables, legumes, nuts, whole grains, herbs and spices, fish and poultry and moderate consumption of red wine.(6,7, 8, 9). WHO recommends consuming less than 2000 mg of salt per day and consuming potassium rich foods (beans, bananas). (10)
- Exercise and weight loss: Regular aerobic exercise can decrease your BP and help you lose weight. (11) Recommended exercise routine would include daily brisk walk for at least 30 minutes, 5 days a week. Blumenthal et al studied the influence of DASH diet, exercise, and weight loss on blood pressure in overweight and obese patients, and found a significant reduction in BP and the risk of developing cardiovascular disease in the study participants after 4 months. (12)
- De-stress and get enough sleep: Effective ways to manage stress include meditation, biofeedback, music therapy, yoga, deep breathing, spa treatment and relaxation techniques, getting enough sleep. These measures have been reported to control and prevent the development of stress induced BP. According to the 2008 study by the American Academy of Sleep Medicine, adults sleeping for about 7-8 hours each night. However, sleeping for more than 7-8 hours or less, per night may increase your risk of hypertension.
- Quitting smoking, excessive alcohol, use of illicit drugs such as cocaine and caffeinated drinks.
Complications of Hypertension
Poorly treated or undiagnosed hypertension may cause long term damage to the blood vessels from the excessive pressure. The following complications may arise from uncontrolled hypertension.
- Stroke: High BP if uncontrolled, damages the lining of the arteries and may progress to thickening. The thickened arterial wall may become blocked or weak, bulging out (aneurysm) and may eventually burst. When either of these happens in the brain, it may result in a stroke. The part of the brain that gets its oxygen and nutrients from the artery fails to function efficiently and may lead to paralysis, speech difficulty and sometimes, death.
- Heart attack: When the arteries supplying the heart muscles thicken or are blocked, the heart may stop functioning effectively and may lead to death.
- Kidney failure
- Blindness and visual impairment: High BP damages the blood vessels in the eyes.
- Heart failure: The heart has to work hard in order to pump blood through high pressure vessels. The heart being a muscular organ, thickens and becomes enlarged. Overtime, it becomes fatigued and unable to pump blood effectively. The consequence is that water and salt are retained in the body, this process may result in kidney failure, further worsening the hypertension.
- Dementia: Thickened blood vessels may starve the brain of adequate blood supply leading to memory and/or cognitive impairment, confusion, speech difficulty, disorientation. This type of dementia is referred to as vascular dementia.
References
- World Health Organization. Global status report on noncommunicable diseases 2010.
Geneva, World Health Organization, 2011. - http://apps.who.int/iris/bitstream/handle/10665/79059/WHO_DCO_WHD_2013.2_eng.pdf;jsessionid=FDFDC848EF2F14A0ADFB61BBC25F9EE8?sequence=1
- https://www.webmd.com/hypertension-high-blood-pressure/guide/blood-pressure-causes#1
- Kulkarni S, O’Farrell I, Erasi M, Kochar MS. Sthttps://www.laaloosh.com/ct/health-and-food/food-recipes/my-weight-watchers-recipes/0-points/ress and hypertension. WMJ. 1998 Dec;97(11):34-8.
- https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/mediterranean-diet/art-20047801
- Sayer RD, Wright AJ, Chen N, Campbell WW. Dietary Approaches to Stop Hypertension diet retains effectiveness to reduce blood pressure when lean pork is substituted for chicken and fish as the predominant source of protein. Am J Clin Nutr. 2015;102(2):302-8.
- Savica V, Bellinghieri G, and Kopple JD. The Effect of Nutrition on Blood PressureAnnual Review of Nutrition 2010 30:1, 365-401
- https://health.gov/dietaryguidelines/dga2010/DietaryGuidelines2010.pdf
- http://apps.who.int/iris/bitstream/handle/10665/79059/WHO_DCO_WHD_2013.2_eng.pdf;jsessionid=FDFDC848EF2F14A0ADFB61BBC25F9EE8?sequence=1
- https://reference.medscape.com/medline/abstract/14656957
