HYPERTENSION: THE SILENT KILLER

Blood pressure & Hypertension

Hypertension is a chronic/persistent elevation in blood pressure readings. An individual receives a diagnosis of hypertension if on more than 2 occasions on different days, their blood pressure readings are consistently high. Hypertension is a non-communicable/non-infectious medical condition.

When the heart beats, it contracts/squeezes and sends blood to the rest of the body through arteries, so the pressure this blood puts on the walls of the arteries is called the blood pressure (BP), the amount of blood the heart pumps & the amount of resistance to this blood flow in the arteries is what determines what the blood pressure reading will indicate.

Your blood pressure is best taken after relaxing for at least 5 minutes & when in a seated position with the arm at the level of the heart & feet on the floor. The expected blood pressure for a healthy adult is <120/80mmHg. Expected blood pressure for healthy children varies by age.

One of the reasons, the blood pressure is measured more than once is because it fluctuates over the course of the day and changes with physical exertion, stress, pain, extreme temperature changes (heat or cold), however, this change is only transient as BP eventually returns to its normal level. It is also elevated in some individuals when in a hospital setting or in the presence of a health care personnel due to anxiety (white coat hypertension).

Understanding blood pressure values

When blood pressure is measured, 2 values are obtained, the upper & the lower one, they are termed the systolic and diastolic blood pressures respectively. The unit of measurement is millimeters of mercury. An individual with a blood pressure of 120/80 mmHg has a systolic blood pressure of 120 & diastolic blood pressure of 80. The systolic reading indicates the force the heart exerts on the walls of the arteries every time it is beating & the diastolic indicates the pressure in the arteries when the heart is resting (to fill up with blood).

Types of Hypertension

• Essential hypertension is elevated blood pressure that does not have an identifiable secondary cause. It is the most common type (90% of cases) & is otherwise called primary hypertension.
• Secondary hypertension is blood pressure that is chronically elevated because of another condition that can be treated or cured which would in turn, lower blood pressure. It is suspected in treatment resistant hypertension despite strict drug adherence, in individuals with no family history of high blood pressure, in previously healthy young people (<18). BP is usually elevated here from kidney failure, structural abnormalities of some blood vessels, an excessive production of hormones that typically raises blood pressure, etc.

Symptoms of Hypertension

Hypertension is referred to as “the silent killer” because individuals who have it are typically asymptomatic (do not have symptoms or warning signs) as symptoms only appear after significant damage has been done to the heart, the arteries, and other organs.

Some people experience non-specific symptoms such as early morning headaches, fatigue, visual changes, dizziness, shortness of breath, nausea, confusion, anxiety, chest pain, etc.

When untreated, long-standing hypertension can lead to sudden cardiac death, heart attack, heart failure, stroke, kidney failure. Complications of hypertension is estimated to cause 9.4 million premature deaths every year as only 1 in 5 adults who have hypertension have it under control.

Causes of Essential hypertension

Different individuals have different causal factors that lead to high BP, there isn’t always specific or sole   cause of essential hypertension, however the factors that increase an individual’s likelihood of being eventually diagnosed with high blood pressure include:

• Obesity: In adults, the body mass index (BMI) can be used to screen if one is overweight or obese. If your BMI falls between 18.5 to < 25, you are within the healthy weight range. Higher BMI indicates overweight or obesity. You can calculate your BMI by dividing your weight in kilograms by your height in meters squared. E.g., A 65kg adult man whose height is 165cm (1.65m) has a BMI of 23.87kg/m² & is within the healthy weight range —- (65 ÷ (1.65)² = 23.87 kg/m²)
• A genetic predisposition: Individuals with a family history of hypertension (father, mother, siblings, grandparents have been diagnosed with hypertension) more likely to be diagnosed with elevated blood pressure than one whose relatives do not have a high BP.

Other possible causes of Hypertension

• A sedentary lifestyle, diabetes mellitus or insulin resistance, high salt intake, smoking, high alcohol consumption, aging, too little potassium in the diet, etc.
• Pregnancy: A previously healthy woman can develop hypertension mid-pregnancy (this is called gestational hypertension) but this usually resolves 12 weeks postpartum.  However, her risk of developing hypertension in the future and or during subsequent pregnancies is now higher. Paradoxically, normotensive & hypertensive patients may experience a drop in blood pressure in the 2^nd and early 3^rd trimester, this goes back to its previous state later in the 3^rd trimester.
• Blood pressure can also be significantly raised with the use and or abuse of certain drugs, e.g., being on Monoamine oxidase inhibitors & eating cheese, beer (antidepressants, also used for other nervous system disorders), cocaine, amphetamines, etc.

Prevention

The most significant way hypertension can be prevented is through lifestyle modification (making positive lifestyle changes).

• Weight reduction. Try to attain and maintain a BMI of <25kg/m², a waist circumference of <40inches (102cm) in men & <35 inches (88cm) women.
• Routine health checkups. About 46% of adults with hypertension do not know they have elevated blood pressure.
• Exercise at least 3 to 5 times a week for a minimum of 30 minutes.
• Consciously make healthy food choices. Eat more fruits, vegetables, whole grain foods (oatmeal, brown rice, quinoa, whole wheat products, bulgur), fish, & low-fat diary products.
• Managing stress.
• Limit your daily sodium intake. Aim to consume no more than 2.4g of sodium (<1 teaspoon of salt). Reducing salt intake by 1g every day lowers systolic BP by 3-4mmHg.
• Control your cholesterol levels by limiting your intake of saturated fats (white chocolate, palm oil, coconut oil, margarine, butter, baked products, ice cream)
• Increase your potassium intake (bananas, coconut water, beets, leafy greens, broccoli, tomatoes, avocados, sweet potatoes, watermelon).
• Reduce your consumption of red meat, processed/canned food, fried food, fast food, reduce the rate of unnecessary snacking. Cut down on your caffeine intake.
• QUIT SMOKING & limit your alcohol consumption.
• Get enough sleep, at least 7 hours every night
• Closely manage or monitor other existing medical conditions you might have with your physician.

Management

There are several medications to control elevated blood pressures, therefore, the drug prescribed to an individual is dependent on their symptoms or any underlying other condition.

Some of these drugs include Hydrochlorothiazide, Spironolactone, Furosemide, Losartan, Amlodipine, Chlorthalidone, Captopril, Lisinopril, Candesartan, Propranolol, Carvedilol, Hydralazine.

While receiving a diagnosis of Hypertension can be initially scary & seem burdensome, the associated complications are totally avoidable by early intervention which includes making positive lifestyle changes as stated in the “prevention” section above, using your medications as prescribed & regularly monitoring your blood pressure.

In cases of treatment resistant hypertension (BP remains >140/90mmHg despite strictly taking 3/more antihypertensives including a diuretic), discuss with your physician to consider doing further diagnostic tests such as Renin: Angiotensin test, Metanephrine urine test, CT scans etc. to rule out secondary causes. Secondary hypertension is curable if there the underlying cause is treated.

Individuals taking any antihypertensive medication should carefully read the label of over-the-counter medications that they buy as some may interact with the drugs they are already taking to lower their blood pressure & if contemplating taking herbal supplements, properly review the ingredients and their concentrations or consider speaking with your physician to rule out potential drug-drug interactions.

Some medications can worsen underlying conditions (kidney disease, lung conditions) or may cause electrolyte imbalance, so it is best to only use drugs as prescribed to you by your physician.