Check for accuracy “If the systolic blood pressure (the top number) on your cuff is within 10 points of the monitor, then it's generally accurate,” he says. Most home blood pressure machines last for about two or three years. After that, check it at your doctor's office annually to make sure it's still accurate.
If a cuff is too small or too large, errors in measurement can occur. Adding to inaccuracy are automated devices that have not been tested for accuracy, which can account for errors in systolic BP.
The study found: Blood pressure readings taken at home were consistent with ABPM. Blood pressure readings based on follow-up clinic visits were significantly lower for the systolic measure, leading to over half of the people with hypertension based on ABPM being missed.
Keep your home blood pressure monitor calibrated
Automatic blood pressure monitors need to be re-calibrated at least once every two years – the instructions that come with your monitor will say how often. This is where the monitor is tested and adjusted to make sure it's giving you accurate results.
All sphygmomanometers should be checked and calibrated by an accredited laboratory at least annually. Aneroid sphygmomanometers should be calibrated every 6 months.
Usually, blood pressure starts to rise a few hours before a person wakes up. It continues to rise during the day, peaking in midday. Blood pressure typically drops in the late afternoon and evening. Blood pressure is usually lower at night while sleeping.
A cuff that is too snug or too loose on the mid-upper arm can lead to greatly exaggerated blood pressure measurements, results of a community-based study show.
Everyone's blood pressure rises and falls many times during the course of a single day, sometimes even within minutes. Many factors contribute to these changes, including physical activity, emotion, body position, diet (especially salt and alcohol intake), and sleep deprivation.
Your first blood pressure reading will almost always be higher than the second due to a wide range of factors, both environmental and psychological. These factors include white coat syndrome, stress, and having a full bladder.
“It's actually quite normal to have variation in blood pressure readings, even within a few minutes,” says Marjorie Willett, nurse practitioner at Aurora Lakeland Medical Center. “Factors that may create changes include physical activity, emotion, diet (especially salt and alcohol intake), and sleep deprivation.”
Systolic pressure (the first number in a blood pressure reading) measures the force with which the heart pumps blood into the arteries. Diastolic pressure (the second, lower number) reflects the pressure in the arteries when the heart rests between beats.
You're using the wrong-sized cuff
The most common error when using indirect blood pressure measuring equipment is using an incorrectly sized cuff. A BP cuff that is too large will give falsely low readings, while an overly small cuff will provide readings that are falsely high.
Anxiety doesn't cause long-term high blood pressure (hypertension). But episodes of anxiety can cause dramatic, temporary spikes in blood pressure.
Don't eat or drink anything 30 minutes before you take your blood pressure. Empty your bladder before your reading. Sit in a comfortable chair with your back supported for at least 5 minutes before your reading. Put both feet flat on the ground and keep your legs uncrossed.
The international BP guidelines for the use of home BP [12–14] have stated that when a series of readings is taken, a minimum of two readings should be taken at intervals of at least 1 min, and the average of those readings should be used to represent the patient's blood pressure.
Conclusions. Single-arm measurements, compared to double-arm measurements, may underestimate the prevalence of hypertension. However, if double-arm measurements are unavailable, right arm is preferred for measurement of BP, especially in women.
Call 911 or emergency medical services if your blood pressure is 180/120 mm Hg or greater and you have chest pain, shortness of breath, or symptoms of stroke. Stroke symptoms include numbness or tingling, trouble speaking, or changes in vision.
Walking lowers systolic blood pressure by 4.11 mm Hg (95% CI, 3.01 to 5.22 mm Hg). It lowers diastolic blood pressure by 1.79 mm Hg (95% CI, 1.07 to 2.51 mm Hg) and resting heart rate by 2.76 beats per minute (bpm; 95% CI, 0.95 to 4.57 bpm).
Still, you can make lifestyle changes to bring your blood pressure down. Something as simple as keeping yourself hydrated by drinking six to eight glasses of water every day improves blood pressure. Water makes up 73% of the human heart,¹ so no other liquid is better at controlling blood pressure.
A digital blood pressure monitor will not be as accurate if your body is moving when you are using it. Also, an irregular heart rate will make the reading less accurate. However, digital monitors are the best choice for most people.
There are some drawbacks to the digital monitor. Body movements or an irregular heart rate can affect its accuracy. Some models only work on the left arm. This can make them hard for some patients to use.