Your blood pressure can vary so much throughout the day that a single measurement in a doctor’s office can give you a diagnosis of high blood pressure when you don’t have it, or miss high blood pressure when you do have it. I think that everyone should have a blood pressure cuff at home so they can monitor their own blood pressure. I recommend getting an arm blood pressure cuff rather than a wrist cuff because the arm cuffs are more dependable. They are inexpensive and are available at any drug store or online.
A normal blood pressure is 120/80 mm Hg or lower. If your blood pressure is consistently higher than 130/80, you have high blood pressure and you can expect your blood pressure to rise higher as you age, since your blood vessels stiffen with aging. About 50 percent of North American adults have high blood pressure, a major risk factor for heart attacks, strokes, diabetes, and premature death. You can’t depend completely on blood pressure measurements done only in a doctor’s office because being active, having “white coat syndrome,” (feeling nervous or stressed), or an improper hurried measurement can raise blood pressure considerably. In one study, systolic blood pressure was 7.3 mm Hg higher in a doctor’s office than when measured more precisely in a research setting (JAMA Intern Med, 2020 Dec 1;180(12):1655-1663).
How To Take Your Own Blood Pressure Properly
When and how you check your blood pressure can affect your results.
• Take your blood pressure after sitting quietly for at least five minutes, preferably either before you go to sleep at night or early in the morning, at least five minutes after you wake up and start moving around.
• Don’t smoke, drink caffeinated beverages or exercise for at least an hour before checking your blood pressure.
• Don’t talk while taking your blood pressure.
• Make sure your bladder is comfortably empty.
• Sit on a chair with your arm on a table or desk, with your palm facing up.
• Sit with your back straight and well-supported. Do not cross your legs.
• Keep your upper arm where you will place the cuff at heart level.
• Make sure the cuff fits snugly with no looseness on the upper arm.
• Take two or three readings at least one minute apart. Do this for a week, and average the readings. If the average is over 120/80, your blood pressure is too high.
Factors That Can Raise Your Blood Pressure Readings
A study of 2,300,000 blood pressure measurements taken by Kaiser Permanente Southern California showed the wide variety of factors that can falsely raise blood pressure (Permanente Journal, 2009;13(3):51-54), including:
• blood pressure cuff too small
• blood pressure cuff not snug at the start
• blood pressure cuff placed over thick clothing
• not resting for five minutes before taking the reading
• exercising or eating beforehand
• not supporting arms, legs, feet or back, which can cause muscles to contract and raise blood pressure
• crossing the legs
• holding arms above or below heart level
• feeling excited
• thinking about an emotional situation
• having taken in alcohol or caffeine
• having a full bladder
• having taken certain medicines such as cold remedies or allergy pills
• having eaten certain foods such as those that contain tyramine (fermented, pickled or cured foods)
• room temperature too hot or too cold
Lifestyle Changes to Lower High Blood Pressure
Many people don’t know that they have high blood pressure because they may have no symptoms. High blood pressure is defined as anything greater than 130/80 by almost all medical groups, including the American Heart Association and the American College of Cardiology. The numbers used to be 140/90, but that misses a lot of people who could have been saved from a preventable premature death just by making some lifestyle changes (Annals of Internal Medicine, March 6, 2018). A study called the SPRINT TRIAL showed that bringing blood pressure below 120 significantly reduces heart attack and stroke risk (N Engl J Med, 2015; 373:2103-2116). Having a systolic blood pressure over 130 doubles your chances of suffering a heart attack, stroke, or heart or kidney failure, and puts you at increased risk for developing dementia in later life. Known causes of high blood pressure include diabetes, pregnancy, dehydration, cardiovascular disease, obstructive sleep apnea, kidney disease, thyroid problems, nervous system problems, and so forth.
Most people with a systolic blood pressure between 130–140 mm or diastolic blood pressure between 80–90 mm can reduce their blood pressure to 120/80 or lower without taking medication, by losing weight, eating healthful foods, cutting down on salt, increasing potassium-rich foods, exercising regularly and not smoking or drinking. Check with your doctor.
If your average systolic blood pressure is over 120 or your average diastolic pressure is over 80, you should immediately make all the lifestyle changes necessary to lower it. Your doctor may feel that you need medications to lower high blood pressure, but lifestyle modifications can often bring your blood pressure to normal so it may not be necessary for you to stay on medication.
Lifestyle changes to lower blood pressure include:
• lose weight if overweight
• eat lots of vegetables, fruits, nuts, beans and other seeds
• avoid sugared drinks (including fruit juices) and sugar-added foods, red meat, processed meats and fried foods
• get plenty of exercise
• keep your blood levels of hydroxy-vitamin D above 30 ng/mL
Your doctor may prescribe medications but you will still want to make these lifestyle changes. See Treat High Blood Pressure with Lifestyle Changes and Blood Pressure Guidelines