Basic knowledge you should know about Blood Pressure
What is blood pressure?
In the most basic sense, blood pressure is a way of measuring how much force is being exerted on the walls of your blood vessels (artery) as blood flows through them.
- Systolic is the top number. It represents the pressure as your heart contracts to pump blood to the body.
- Diastolic is the bottom number. It represents the pressure between beats, when your heart relaxes.
The following shows the different stages of hypertension (also known as high blood pressure):
“Out-of-office BP measurements are recommended to confirm the diagnosis of hypertension and for titration of BP-lowering medication, in conjunction with telehealth counseling or clinical intervention… Self monitoring of BP refers to the regular measurement of BP by an individual at home or elsewhere outside the clinic setting (source: AHA/ACC 2017 High Blood Pressure Clinical Practice Guideline).”
2013 ESH/ESC Guidelines for the Management of Arterial Hypertension defines high blood pressure readings obtained by self-measurement at home as:
Systolic Blood Pressure ≥ 135
Diastolic Blood Pressure ≥ 85
In terms of taking action based on your blood pressure readings, this should always be discussed and decided on between you and your doctor. You should never self-diagnose or adjust your medication if not prescribed by your doctor.
To learn more about blood pressure, click on the following links:
- American Heart Association: Understanding Blood Pressure Readings
1 ACC & AHA 2017 High Blood Pressure Clinical Practice Guideline
What is more important — the Systolic or Diastolic reading?
Both readings are important. One measures your blood pressure during a heart contraction and the other measures blood pressure between heart contractions. For your particular situation, you should discuss both measurement results with your doctor.
Is it normal for my blood pressure to vary?
Yes, it is quite normal for people’s blood pressure to change throughout the day and night, or in different settings where you may measure your blood pressure. Many things, such as stress levels, food or drink intake, activity levels, even time of day can all affect a person’s blood pressure reading at any given time. In fact, there are published studies that show a given person’s blood pressure can change by up to 20mm within a day, based on activity levels, food/drink intake, stress, etc. This is why it is important to take your blood pressure on a regular basis, and review the overall trend of your blood pressure readings with your doctor.
What can I do to help better manage my blood pressure?
Managing your blood pressure doesn’t have to take a lot of work. In fact, small improvements to your lifestyle can help.
Exercise: Just be a little more active. Walk instead of drive; take the stairs instead of the elevator, etc.
Eat Smart: Try to find low-fat, low-sodium substituted that also taste great. Potassium found in bananas and carrots is nature’s best medicine for your heart.
Kick the Habits: Minimize your alcohol and cigarette intake.
Stifle Your Stress: Stress is a normal part of life. But too much can increase the risk of heart disease. Relax by doing things you enjoy (yoga, gardening, walking, etc.) and your heart can benefit.
Monitor Your Blood Pressure at Home: Monitoring your blood pressure at home on a regular basis provides you and your doctor with the information to best manage your blood pressure.
These are just some examples. Discuss with your doctor on other ways how you can better your heart.
My blood pressure is not responding to the medications my doctor prescribe. What should I do?
You should contact your doctor and discuss the situation. Only your doctor is qualified to diagnose and prescribe medication, or make changes to medications in managing blood pressure.
Why should I monitor my blood pressure at home?
The American Heart Association recommends that anyone with, or at risk of high blood pressure, should monitor their blood pressure at home. Home blood pressure monitoring is one of the best methods of trending a person’s blood pressure in their own environment.
Click here for more information from the American Heart Association on who should monitor at home, and why.
What is the difference between monitoring blood pressure using a home digital monitor as opposed to getting my reading when I see my doctor?
Digital monitors measure blood pressure oscillometrically rather than by auscultation. In auscultation, stethoscopes are used to take blood pressure by listening for specific heartbeat sounds which the doctor then uses to determine systolic and diastolic pressures. Oscillometric technology measures the vibration of blood traveling through the arteries and converts the movement into digital readings.
iHealth digital blood pressure monitors use the oscillometric method of blood pressure measurement. An oscillometric monitor does not need a stethoscope so the monitor is simple to use.
It is also important to note that Home Blood Pressure monitoring allows you to monitor frequently and share the results with your doctor if you desire.
What does Oscillometric technology mean?
Oscillometric technology measures the vibration of your blood traveling through your arteries and converts the movement into digital readings.
Are the readings different between an upper arm blood pressure monitor and a wrist blood pressure monitor?
It is quite possible that your readings may be different from your upper arm to your wrist as blood pressure varies throughout the human body. All iHealth blood pressure monitors, whether upper arm or wrist, are validated in the same manner and have the same accuracy specifications. In terms of which type of blood pressure monitor is best for you, we recommend that you discuss this with your doctor, based on your individual needs.
Are digital blood pressure monitors accurate?
All iHealth blood pressure monitors are clinically proven accurate. They are clinically validated to be within the following:
- Blood pressure: within +/- 3 mgHg or 2 percent
- Pulse: within +/- 5 percent of reading.
This meets or exceeds the AAMI (Association of Medical Instrumentation) standards. To understand the accuracy levels of other manufacturer’s blood pressure monitors, you need to contact them. It is always important to investigate accuracy and ease of use before purchasing a home blood pressure monitor.
Will I see differences between my readings at home compared to readings in my doctor’s office?
Yes, you will see some differences. This is normal and can occur for many reasons. Some of the more common reasons are:
- A person’s blood pressure varies throughout the day, so at any given moment your blood pressure can change.
- In terms of the amount of change; there are published studies that show a given person’s blood pressure can change by up to 20 mm within a day, based on activity levels, food/drink intake, stress, etc.
- You may have a condition known as “White Coat Hypertension.” This is a condition in which a blood person’s blood pressure rises above its usual level when it is measured in a doctor’s office or clinical setting.
- You may have a condition known as “Masked Hypertension.” This is a situation in which a person’s blood pressure falls below its usual level when it measure in a doctor’s office or clinical setting.
So do not be alarmed when you see differences between your readings at home compared to your readings in your doctor’s office. Discuss it with your doctor to get the best overall picture of your heart health.
What are the common causes of getting blood pressure readings that are inaccurate?
It is quite normal for people’s blood pressure to change throughout the day and night, or in different settings where you may take your blood pressure. Many things, such as stress levels, food or drink intake, activity levels, even time of day can all affect a person’s blood pressure reading at any given time. So, it is possible that you may just be seeing normal fluctuations in blood pressure.
However, below are some common situations that can lead to inconsistent or inaccurate readings:
Using the wrong cuff size for your arm
Just because the cuff may fit around your arm does not mean it is the right size cuff for you. The correct cuff size is directly related to the circumference of your arm. To get accurate readings, it is important that you are using the correct sized arm cuff. To determine your arm size, use a cloth tape measure and place midway between your elbow and your shoulder around the circumference of your upper arm. Wrap the tape measure evenly around your arm. Do not pull the tape tight. Note the precise measurement in inches. Select an iHealth home blood pressure monitor with the right size of cuff included, or if you already have the monitor, and need a different sized cuff, contact our consumer support line at 855/816-7705, and they can assist you to purchase the right size accessory cuff for your unit.
Not using the cuff correctly
Make sure you are wrapping the cuff around your arm in the correct position. After wrapping the cuff around your arm, check the location of the brachial artery marker. The air tube should run down the center of your arm. The cuff should not be wrapped too tight or too loose. Look at the instruction manual for the monitor to get more detailed instructions on the specific cuff included with your unit.
Activities right before taking a measurement
Avoid eating, drinking alcohol or caffeinated beverages, smoking, exercising and bathing for 30 minutes prior to taking a measurement. It is also best to rest for 15 minutes before starting the measurement. Avoid taking a measurement during stressful times. Take the measurement in a quiet place.
Incorrect body position or moving too much
Sit in a chair with your feet flat on the floor. Rest your arm on a table with your palm facing upward. The cuff should be level with your heart. Do not talk or move during the measurement.
Timing of taking measurements
Try to take readings at the same general times each day (for example, once in the morning and once at night) for comparison purposes.
What are some common reasons why my blood pressure readings seem higher than expected?
There are many reasons why blood pressure readings may seem high. Below are some of the common reasons and the estimated ranges of how much readings can vary. It is important to ensure you are using the monitor as it was intended, so please make sure you are following the directions in the instruction manual, or call our consumer support line at 855/816-7705 if you have questions. It is also important to note that if you can continue to see high readings, discuss with your doctor or a medical professional — it is possible that your blood pressure is actually higher than what you believe it to be.
Factors Affecting Accuracy of Blood Pressure Monitors¹
Magnitude of systolic/diastolic blood pressure discrepancy (mm Hg)
|Talking or active listening||10/10|
|Cuff over clothing||5-50/|
|Cuff too small||10/2-8|
|Smoking within 30 minutes of measurement||6-20/|
|Arm unsupported, sitting||1-7/5-11|
|Arm unsupported, standing||6-8/|
¹Handler J, The Permanente Journal 2009; 13:3:51-54
Are there differences between taking a blood pressure reading on the right arm vs. left arm?
Blood pressure measurement values vary from the left arm to the right arm. The average is generally within 10 mmHg (millimeters of mercury) for most individuals. iHealth home blood pressure monitors are generally designed for use on the left arm as they are validated through clinical studies using the left arm. You should talk to your doctor before using the right arm to take a measurement.
My doctor wants to compare the reading from my home BP monitor with the reading taken in the office. What are the instructions on how to do this?
When doing this type of a comparison, it is very important that the measurements are taken in a certain manner in order for the reading on the iHealth monitor to be accurate. The iHealth monitor uses oscillometric technology that measures the vibration of the blood as it moves through the arteries. The doctor is using a different method of measurement and listens to the sound of your heart. It is necessary for the doctor to take the first measurement using the iHealth monitor. The brachial artery is fully open and not restricted so vibration of the blood is accurately measured. It is also important to note that the different test methods may give slightly different readings due to the test methods or due to the normal fluctuation in blood pressure.
Why is my wrist blood pressure monitor giving high readings?
The most common cause of high readings when using a wrist blood pressure monitor is because the user does not have the wrist monitor at heart level. When using a wrist monitor, pleas ensure the device is at heart level when taking a reading. Also note that there may be actual differences between your blood pressure at the upper arm site and the wrist site.
Does the size of the cuff matter?
Yes, it is very important to use the appropriate size cuff for your arm in order to get accurate measurement results when using your home blood pressure monitor. If you use the wrong sized cuff, you will likely experience inaccurate readings, inconsistent readings and error messages from the device.
What size cuff do I need?
The correct size of cuff is based on the circumference of your upper arm, or your wrist, depending on which type of model you want. iHealth monitors cover a variety of sizes as mentioned below:
iHealth Ease Smart Blood Pressure Dock Cuff circumference:
- Standard: 8.66″ – 14.7” (22 cm – 36 cm)
- Optional :Large: 11.8″ – 16.5″ (30 cm – 42 cm)
- Optional :Extra Large: 16.5″ – 18.9″ (42cm – 48cm)
iHealth Feel Smart Blood Pressure Cuff Monitor Cuff circumference:
- Standard: 8.6” – 16.5” (22 cm – 42 cm)
- Optional: XL: 16.5″ – 18.9″ (42 cm – 48 cm)
- 5.3” – 8.7” (13.5cm – 22cm)
iHealth Track Smart Blood Pressure Monitor Cuff circumference:
- Standard:8.7″ – 16.5″ (22 cm – 42 cm)
iHealth Clear Smart Blood Pressure Monitor Cuff circumference:
- Standard: 8.6” – 16.5” (22 cm – 42 cm)
- Optional XL: 16.5″ – 18.9″ (42 cm – 48 cm)
How do I measure my arm circumference?
To determine your arm size, use a cloth tape measure and place midway between your elbow and your shoulder around the circumference of your upper arm. Wrap the tape measure evenly around your arm. Do not pull the tape tight. Note the precise measurement in inches. Determine which size cuff is best for you, then purchase a home blood pressure monitor with that size cuff included.
How do I know if I have put on the arm cuff correctly?
We recommend you apply the cuff using the following directions. First, make sure you have removed any tight-fitting clothing from your left arm. Put your left arm through the cuff loop. The bottom of the cuff should be about one-half inch above your elbow. Turn your arm so your palm is facing up. Adjust the cuff around your arm so that the tubing runs down the center of your arm. Secure the cuff so it stays in place.
I keep getting error messages when I try to take a reading. What should I do?
In the instruction manual that came with the unit, there is a section included on on the different types of error messages. Please review this section of the manual. You can locate electronic instruction manuals in our Support Page.
If this does not fully resolve the issue, please contact the iHealth consumer support line at 855/816-7705 or e-mail us your question.
Can I take a blood pressure reading measurement during exercise?
iHealth Smart blood pressure monitors are NOT intended for use during exercise or activity. We recommend that you avoid eating, drinking alcohol or caffeinated beverages, smoking, bathing and exercising for at least 30 minutes before taking a measurement. It is also best to rest for 15 minutes before starting the measurement.
What is the warranty for the cuff on my blood pressure monitor?
For most models, the warranty coverage for the arm or wrist cuff is one year. Cuffs will need to be periodically replaced throughout the life of the monitor. When purchasing a replacement cuff for an upper arm unit, please be certain to measure the circumference of your arm to purchase the correct cuff size. Please check the instruction manual for your specific unit.
Can I file an insurance claim for the purchase of my blood pressure monitor?
Because insurance plans vary widely, you should contact your individual insurance company to determine what level the purchase of a home blood pressure monitor would be covered.
Are iHealth blood pressure monitors FDA approved?
All iHealth home blood pressure monitors are required to go through a FDA inspection and clearance process (known as 510(k)) prior to marketing.
How do I get my monitor repaired?
You need to contact our consumer support line at 855/816-7705 or e-mail us .The representative will discuss the situation with you, and help determine if you need to send it in for inspection.
Where do I purchase accessories for my iHealth blood pressure monitor?
If you know the accessory you need or want, you can purchase via the iHealth Webstore. If you are not fully sure what accessory you need, please contact our consumer support lineat 855/816-7705 or e-mail us , and they can assist you. They also can place the order for you during the same call.