Blood pressure is the force that blood exerts on the walls of your arteries as it circulates. This force is necessary for blood to carry oxygen and nutrients to all parts of your body.
Your blood pressure is measured with a systolic number (SBP) and a diastolic number (DBP). Systolic blood pressure occurs when your heart contracts and is the higher of the two numbers. Diastolic blood pressure is the lower number and occurs when your heart releases and fills with blood. The higher your systolic and diastolic blood pressure is and the longer it stays there, the more damage that can occur to your blood vessels.
Hypertension Canada’s Canadian Hypertension Education Program (CHEP) establishes the following criteria for diagnosing hypertension:
140/90 mm Hg or lower for most people
135/85 mm Hg or lower if measuring your pressure at home (you are less stressed or nervous at home)
Lower than 130/80 mm Hg if you have diabetes
In November 2017, the American Heart Association and the American College of Cardiology published new standards for diagnosing hypertension in the United States. While these standards have not yet been implemented in Canada, they could serve as a future benchmark for Hypertension Canada. The new criteria are as follows:
Normal: lower than 120/80 mm Hg
Elevated: systolic pressure between 120-129 and diastolic pressure lower than 80
Stage 1 hypertension: systolic pressure between 130-139 or diastolic pressure between 80-89
Stage 2 hypertension: systolic pressure at 140 or higher and diastolic pressure at 90 or higher
Hypertensive crisis: a systolic pressure greater than 180 and/or a diastolic pressure greater than 120
HTN is a cardiovascular disease that is generally asymptomatic, meaning that it does not exhibit symptoms. However, very high and sustained blood pressure (moderate to advanced stage) can cause headaches accompanied by fatigue (often localized at the back of the neck), vertigo, buzzing in the ears, palpitations, nose bleeds, vision problems, confusion and numbness or tingling in the feet and hands.
Causes and Consequences
There are mainly two types of HTN depending on the causes: essential or primary hypertension does not have any obvious causes and is responsible for 90% of cases, but several factors need to be considered, such as heredity, age and lifestyle; and secondary hypertension, which is generally caused by a specific disease (e.g. kidney disease, diabetes, cardiovascular disease).
According to the American Heart Association, the most common risk factors for developing hypertension are:
Excessive levels of salt in the blood (or sodium intake greater than 1500 milligrams per day) and excessive sugar and fat intake;
Diabetes and hypercholesterolemia;
Sleep apnea, a respiratory condition in which oxygen levels decrease dramatically during sleep, increasing blood pressure and adding stress to the cardiovascular system. Those with obstructive sleep apnea are at higher risk of developing hypertension;
Obesity is linked to many different factors such as sedentary lifestyle, bad diet, excessive intake of salty foods, hyperinsulinism, etc. Each of these conditions eventually causes a thickening of the arteries as well as conditions such as diabetes, heart attacks and even strokes;
A long-term sedentary lifestyle;
Excessive alcohol use or drug use (e.g., cocaine, amphetamine and crystal meth) can cause unbearable pressure on the heart and arteries and cause permanent damage;
Smoking contributes to a constriction and narrowing of the arteries, and this is strongly linked to heart disease;
Some hormonal diseases (e.g., Cushing syndrome, caused by excessive production of steroid hormones) could also cause blood vessel constriction and therefore hypertension;
The presence of kidney disease – in this case, the adrenal glands (small pea-shaped glands just above the kidneys) secrete excess cortisol, which can raise blood pressure.
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In the long term, hypertension is also a major risk factor for many diseases, including heart attack and heart failure, stroke, kidney failure, vision loss, reduced blood flow to the brain and aneurysms.
If you do not have risks associated to heredity or secondary hypertension, you can prevent hypertension by adopting a healthy lifestyle and diet. Hypertension Canada recommends that you:
Engage in moderate physical activity for 30 to 60 minutes, nearly every day of the week (“moderate” means you sweat a bit and breathe a little harder than usual)
Lose weight if you are obese
If you think you have sleep apnea, get a diagnosis
Adopt healthy eating habits
Reduce your salt or sodium intake and remember that most of the sodium you get is from processed or packaged foods as well as restaurant or take-out food. Wash canned foods and other salty foods in water before eating or cooking them
Read the labels on the foods you buy and look for packaged foods that provide 5% or less of daily sodium intake
Achieve your healthy weight or, in other words, a healthy body mass index (BMI) of 20-25
Manage your stress levels to improve your coping skills and health
Limit your alcohol consumption to 1 or 2 drinks per day or less