Most errors in blood pressure readings are caused by the blood pressure cuff size. One study⁵ showed that a larger cuff size overestimated the blood pressure measurements by three to five points, while a smaller cuff size overestimated the results by two to six points.
Acute meal ingestion, caffeine or nicotine use can all affect BP readings, leading to errors in measurement accuracy. If the patient has a full bladder, that can lead to an error in systolic BP of up to 33 mm Hg, and the white-coat effect can have an error of up to 26 mm Hg.
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.
Inaccurate blood pressure measurement could lead to incorrect diagnosis and inappropriate treatment. The chance to reduce the risk of heart attack or stroke could also be missed. Over 3000 blood pressure monitors are available but less than 15% of these have been properly tested for accuracy.
Incorrect patient positioning
Perhaps the most common mistake in blood pressure measurement is allowing patients to sit or lie with their arms hanging by their side, since when the upper arm is below the level of the right atrium, the readings will be too high.
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.
The diagnosis of hypertension may be off the mark if doctors go by the results of just one blood pressure test, a study conducted across 15 states found, with 24 per cent of people getting wrongly diagnosed as hypertensive.
You could have white coat hypertension. This condition occurs when blood pressure readings at a health care provider's office are higher than they are in other settings, such as at home. It's called white coat hypertension because people who measure blood pressure sometimes wear white coats.
At the beginning, measure your blood pressure at least twice daily. Take it first in the morning before eating or taking any medications. Take it again in the evening. Each time you measure, take two or three readings to make sure your results are the same.
The resulting anxiety can elevate blood pressure 10 points or more.” Studies have shown that clinics rarely take two or more blood pressure readings, even though the ACC/AHA guidelines suggest that doing so could reduce the effects of WCH.
Blood Pressure Cuff Placement
If the cuff is too small, it can add 2 to 10 points to your bp measurement. Be sure to roll up your sleeve for a blood pressure test and also let your doctor know if the cuff feels too tight around your arm.
Blood pressure has a daily pattern. 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.
The simplest way to measure your own blood pressure is to purchase an automated cuff. Automatic blood pressure machines are easy to use, and they're helpful if you have any hearing impairments. These types of blood pressure cuffs have a digital monitor that will display your blood pressure reading on a screen.
But home blood pressure monitors aren't always as accurate as they should be. "Home blood pressure monitors may be inaccurate in 5% to 15% of patients, depending on the threshold for accuracy used," according to Dr.
Don't check your blood pressure too often.
Some people find that they become worried or stressed about small changes in their readings if they take them too often. Worrying can also raise your blood pressure in the short term, making your reading higher than it should be.
Blood pressure changes throughout the day. Your blood pressure is typically at its lowest right after waking up. It tends to vary by up to 30% across the day. This is because of hormone changes, activity level, and eating.
It's normal for blood pressure to vary somewhat throughout the day. Stress, exercise, and sleep can all make a difference. But if your blood pressure often changes significantly from one healthcare visit to another, there may a problem.
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.
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.
In the US, 47% of adults suffer from hypertension (higher than normal blood pressure). ¹ While blood pressure can fluctuate throughout the day, a long-term increase can lead to serious health problems, including strokes and heart disease. Temporary blood pressure spikes aren't always a cause for concern.
Blood pressure is the pressure of blood on the walls of your arteries as your heart pumps blood around your body. Blood pressure does not stay the same all the time. It changes to meet your body's needs and it is normal for your blood pressure to go up and down throughout the day.
Anxiety, stress, drugs, alcohol, physical exercise, and a range of medical conditions such as sleep apnea and kidney disease can cause your blood pressure to fluctuate from high to low. It's normal to see some variance throughout the day but you should consult a doctor if you exhibit symptoms of labile hypertension.
Blood pressure changes naturally many times a day. Most changes are normal and predictable. When these spikes and valleys in your blood pressure occur, you may not experience unusual signs or symptoms. These fluctuations may be brief and fleeting.