There’s almost always a discussion about your blood pressure when you visit your doctor for a check-up, but how much do you really know about it? Here are a few facts to help you understand why it’s important, how to monitor your pressure and some things you can do to keep your pressure healthy…
What is blood pressure?
Blood pressure (also called “hypertension”) is a measure of the pressure inside your arteries. This pressure increases and decreases with each heartbeat. Your heart pumps out blood with each beat, with enough pressure to send it through the arteries to all parts of the body. This pressure drops between each heartbeat, while the heart relaxes and refills with blood. Your doctor or nurse measures the highest and lowest pressure for each beat, called the “systolic” and “diastolic” measurements.
Blood pressure changes constantly. Exercise, caffeine, smoking, anxiety, stress, and even a full bladder can raise your blood pressure. Relaxing can lower it.
What can high blood pressure do?
Uncontrolled high blood pressure is the number one risk factor for stroke and an important risk factor for heart disease. It can also cause damage to various organs.
Damage to arteries
Under constant high pressure, the inner lining of blood vessels can become damaged and inflamed, allowing fats in the blood stream to collect in the lining. These fatty areas also collect deposits of calcium and are called “plaque”. They can stiffen and eventually block an artery, or they can burst open and cause a blood clot to form, instantly blocking the artery. Some researchers have suggested plaque formation may be the body’s way of protecting and healing damaged areas, somewhat like a scab does on the outside of the body, but this is yet to be proven.
Over time, with constant pressure, a section of artery wall can also become weakened and bulge outward. This is called an aneurysm and, if it bursts, it can cause life-threatening bleeding inside the body. Aneurysms can form in any artery, but they’re most dangerous when they develop in the brain or on the aorta, the body’s largest artery that runs from the left side of the heart down into the abdomen.
Damage to the heart
When blood pressure is high, your heart must work harder to pump blood against this increased pressure. Over time, the left side of the heart that pumps blood through the body can become larger and stiffen because of the extra work it needs to do. This limits the heart’s ability to supply the body with enough blood and to keep up with the blood returning to the heart from the lungs. This is called heart failure (also known as cardiac insufficiency) and it also increases your risk of a heart attack.
Damage to the brain
A stroke occurs when part of the brain is deprived of blood, causing brain cells to die. Uncontrolled high blood pressure can damage blood vessels in the brain, causing them to narrow, burst or leak. It can also cause blood clots to form in the arteries leading to the brain, blocking blood flow and potentially causing a stroke.
Reduced blood flow to the brain can also cause dementia, a result of gradual damage to areas of the brain that control thinking, speaking, decision-making, memory, vision and movement.
Damage to eyes and kidneys
Both the eyes and kidneys contain tiny blood vessels that can become damaged, leading to vision problems and kidney failure.
What is a good blood pressure?
Ideal – 120/80
Normal – less than 140/90
Exceptions:
Diabetes – best if less than 130/80
Over 80 years – less than 150/90 can be acceptable, especially if frail
Note that frail elderly are more susceptible to medication side effects like dizziness and risk of falling, and this need to be taken into account when setting targets
Low blood pressure (less than 120/80) is considered fine unless it is low enough to make you dizzy or lightheaded. A doctor once told me having low blood pressure was “like having extra insurance”.
What can you do to control blood pressure?
Some factors, such as age, ethnicity, and gender, cannot be controlled. After age 65, women are more likely than men to develop high blood pressure. Pregnancy, birth control, and menopause can also increase the chance of developing high blood pressure.
But there is plenty you can do:
Eat a healthy diet. Learn about the DASH diet (Dietary Approaches to Stop Hypertension), an eating plan designed to help lower high blood pressure. This diet includes healthy foods and limits salt intake.
Be active for at least 150 minutes per week, at least 10 minutes at a time.
Maintain a healthy body weight. If overweight, losing even 5% to 10% of your weight can help lower blood pressure and reduce risk of heart attack or stroke.
Don’t smoke!
Limit alcohol to 2 drinks a day/10 per week for women, and 3 per day/15 per week for men.
Find healthy ways to manage your stress.
How to measure blood pressure at home
Read and follow specific instructions for your monitor, then follow these general instructions:
Relax in a quiet area for 5 to 10 minutes. Avoid exercise, caffeine and smoking for 30 minutes before measurement. Empty bladder, if necessary
Slide cuff on arm with lower edge about 1 inch above elbow fold. Fasten snugly but not too tight (should be able to slide 2 fingers underneath). Cuffs come in 3 sizes - be sure to choose the appropriate one for your arm size.
Sit up straight, back against chair, legs uncrossed, arm resting on table, palm up. Relax and don’t talk during the measurement.
If using an automatic monitor, press button now. If not, continue with steps below:
Inflate cuff about 30 points higher than expected measurement, or until the machine says to stop. (some monitors - those without a stethoscope - do the rest automatically).
Loosen airflow valve so that pressure falls by 2 to 3 points with each heartbeat.
With a manual (stethoscope) monitor, listen for the first pulse (heartbeat) sound.
Note the reading on the gauge/screen
This is the upper (systolic) reading
Continue to slowly deflate the cuff
Listen until the heartbeat sound disappears
This is the lower (diastolic) reading
Let cuff completely deflate.
Repeat twice, resting for several minutes between readings. Use the lowest reading.
Record the date, time and lowest measurement. Bring records to your doctor’s visits. Once a year, bring your machine to check its accuracy by comparing with your doctor’s reading. Your doctor, nurse or pharmacist can also check your technique.
High blood pressure can quietly damage your body over a period of years – they call it the “Silent killer”. So, have your doctor check your blood pressure regularly, or check it yourself. Take action if your pressure is consistently increased and prevent blood pressure complications.
References:
High Blood Pressure (Heart and Stroke Association)
Checking Your Blood Pressure at Home (WebMD)
High blood pressure dangers (Mayo Clinic)
Blood pressure targets in the elderly (Journal of Hypertension)
