High Blood Pressure: Checking Your Blood Pressure at Home

Introduction

  • When blood pressure is high, it starts to damage the blood vessels, heart, and kidneys. This can lead to heart attack, stroke, kidney disease, and other problems. But if you don't measure your blood pressure, you won't know when it's high, because there are usually no symptoms.
  • A home blood pressure monitor makes it easy to keep track of your blood pressure.
  • You can check your blood pressure at different times and in different places (such as at home and at work) during the day.
  • Checking your blood pressure at home helps you work with your doctor to diagnose and manage your blood pressure. Checking it at home does not replace having it checked by your doctor.1
 

Blood pressure is a measure of how hard the blood pushes against the walls of your arteries as it moves through your body. It's normal for blood pressure to go up and down throughout the day, but if it stays up, you have high blood pressure.

Blood pressure is recorded as two measurements:

  • Systolic pressure is the highest pressure that occurs when your heart muscles contract.
  • Diastolic pressure is the lowest pressure that occurs when your heart relaxes between beats.

Blood pressures are measured in millimeters of mercury (mm Hg). Systolic pressure, the higher of the two readings, is measured first. Diastolic pressure is the lower reading. For example, if your systolic pressure is 120 mm Hg and your diastolic pressure is 80 mm Hg, your blood pressure is recorded as 120/80, or "120 over 80."

Test Your Knowledge

Many people who have high blood pressure don't know it, because it usually has no symptoms.

  • True
    This answer is correct.

    High blood pressure can lead to heart attack, stroke, and other problems. But if you don't measure your blood pressure, you won't know when it's high, because there are usually no symptoms.

  • False
    This answer is incorrect.

    High blood pressure usually has no symptoms, so measuring your blood pressure may be your only way to know that it is high.

  •  

Continue to Why?

 

When you take your own blood pressure, you can do it at different times and in different places, such as at home, at work, and when you travel. You can partner with your doctor to:

  • Decide whether you have high blood pressure.
  • Check how lifestyle changes, such as weight loss and exercise, are helping to lower your blood pressure.
  • Check whether a certain medicine is helping to lower your blood pressure.
  • See if you have low blood pressure that may be caused by irregular heart rhythms, certain medicines, or other medical conditions.
  • Make sure that any medicines you take for other problems are not causing episodes of high blood pressure.

Some people have a big rise in blood pressure only when they are in a doctor's office. This is called "white-coat hypertension." It might be caused by worry about the doctor visit. By checking blood pressure at home, these people can often find out whether their blood pressure readings generally are lower when they are not in the doctor's office.

Test Your Knowledge

If I take my blood pressure at home, I can help my doctor find out if I have high blood pressure. And I can keep track of how well lifestyle changes and medicine are working to lower my blood pressure.

  • True
    This answer is correct.

    By checking your blood pressure at home, you can help your doctor find out if you have high blood pressure. And you can keep track of how well lifestyle changes and medicine are working to lower your blood pressure.

  • False
    This answer is incorrect.

    By checking your blood pressure at home, you can help your doctor find out if you have high blood pressure. And you can keep track of how well lifestyle changes and medicine are working to lower your blood pressure.

  •  

Continue to How?

 

Blood pressure monitors

There are two types of blood pressure monitors:

  • Automatic monitors. These are easier to use. They do the listening for you.
  • Manual monitors. This is the kind of device you usually see at the doctor's office. It involves using a stethoscope to listen to the heartbeat.

Buying and maintaining a monitor

When you first get a blood pressure device, check its accuracy. Do this by comparing its readings with those you get at the doctor's office. Ask your doctor or nurse to watch you use your device to make sure that you are doing it right and that it works right. It's a good idea to have your device checked every year at the doctor's office.

The size of the blood pressure cuff and where you place it can greatly affect how accurate your device is. If the cuff is too small or too large, the results won't be right. You may have to measure your arm and choose a monitor that comes in the right size.

A monitor that measures blood pressure in your arm is recommended for most people. Blood pressure monitors used on the wrist aren't as reliable as those that use arm cuffs. Wrist monitors should be used only by people who can't use arm cuffs for physical reasons. And devices that use finger monitors aren't recommended at all.2

Check your blood pressure cuff often. Make sure all of the parts of your monitor are in good condition. Even a small hole or crack in the tubing can lead to inaccurate results.

Getting ready

Before you take your blood pressure:

  • Don't eat, smoke, or exercise for at least 30 minutes. And don't use any medicines that can raise blood pressure, such as certain nasal sprays.
  • Rest at least 5 minutes before you take a reading. Sit in a comfortable, relaxed position with both feet on the floor. Don't move or talk while you are measuring your blood pressure.
  • Try not to take your blood pressure if you are nervous or upset.
  • If you can, use the same arm for every reading. Readings may be 10 to 20 mm Hg different between your right arm and your left arm.

Remember that blood pressure readings vary throughout the day. They usually are highest in the morning after you wake up and move around. They decrease throughout the day and are lowest in the evening.

When you first start taking your blood pressure at home, always take your blood pressure 3 times. Wait 1 to 2 minutes between recordings to let the blood flow back into your arm. After you get better at doing it, you probably will need to do it only once or twice each time.

Using an automatic blood pressure monitor

  1. Sit with your arm slightly bent and resting comfortably on a table so that your upper arm is on the same level as your heart.
  2. Wrap the blood pressure cuff around your bare upper arm. The lower edge of the cuff should be about 1 inch (2.5 cm) above the bend of your elbow.
  3. Press the on/off button.
  4. Wait until the ready-to-measure "heart" symbol appears next to zero in the display window.
  5. Press the start button. The cuff will inflate.
  6. After a few seconds, the cuff will begin to deflate. The numbers on the screen will begin to drop.
  7. When the measurement is complete, the heart symbol stops flashing. The numbers tell you your blood pressure and pulse.

Using a manual blood pressure monitor

If you're not familiar with using a stethoscope, you may want to get help from someone who is. The accuracy of a blood pressure recording depends on putting the stethoscope in just the right place.

  1. Sit with your arm slightly bent and resting comfortably on a table so that your upper arm is on the same level as your heart.
  2. Wrap the blood pressure cuff around your bare upper arm. The lower edge of the cuff should be about 1 inch (2.5 cm) above the bend of your elbow.
  3. Close the valve on the rubber inflating bulb. Squeeze the bulb rapidly with your opposite hand to inflate the cuff. Keep squeezing until the dial or column of mercury reads about 30 mm Hg higher than your usual systolic pressure. (If you don't know your usual pressure, inflate the cuff to 210 mm Hg.) The pressure in the cuff will temporarily stop all blood flow in your arm.
  4. Put the stethoscope over the large artery slightly above the inside of your elbow. You can find this artery by feeling for its pulse with the fingers of your other hand. If you are using a cuff with a built-in stethoscope, be sure the part of the cuff with the stethoscope is over the artery. Don't let the stethoscope rub on the cuff or your clothing. This may cause noises that make your pulse hard to hear.
  5. Open the valve on the bulb just slightly. The numbers on the pressure dial or mercury tube should fall gradually—about 2 to 3 mm Hg per second. Some devices automatically control the fall at this rate.
  6. Listen through the stethoscope. As you watch the pressure slowly fall, note the number on the dial or tube when you first start to hear a pulsing or tapping sound. The sound is caused by the blood starting to move through the closed artery. This is your systolic blood pressure.
  7. Continue letting the air out slowly. The sounds will become muffled and finally will disappear. Note the number when the sounds completely disappear. This is your diastolic blood pressure. Finally, let out all the remaining air to take the cuff off.

Keep a blood pressure diary

Keep a blood pressure diary. Your records may help explain changes in your blood pressure readings and help your doctor make sure you get the right treatment.

Everyone's blood pressure changes from day to day and even from minute to minute sometimes. Blood pressure tends to be higher in the morning and lower at night. Stress, smoking, eating, exercise, cold, pain, noise, medicines, and even talking can affect it.

Record your blood pressure numbers with the date and time. You might use a home blood pressure log(What is a PDF document?) or a spreadsheet on your computer. Your monitor might have a feature that will record your numbers for you. Some monitors can transfer this information to your computer.

Also record your daily activities, such as the time you take medicine or if you feel upset or feel stressed.

Test Your Knowledge

The size and position of the blood pressure cuff can affect the reading. I should check my blood pressure while I am seated in a comfortable position.

  • True
    This answer is correct.

    The size and position of the blood pressure cuff can affect the blood pressure reading. It is important that the cuff fits right and is placed on the widest part of the upper arm. Check your blood pressure while you are seated in a comfortable position.

  • False
    This answer is incorrect.

    The size and position of the blood pressure cuff can affect the blood pressure reading. It is important that the cuff fits right and is placed on the widest part of the upper arm. Check your blood pressure while you are seated in a comfortable position.

  •  

Continue to Where?

 

Talk with your doctor

If you have questions about this information, print it out and take it with you when you visit your doctor. You may want to use a highlighter to mark areas or make notes in the margins of the pages where you have questions.

If you would like more information on taking your blood pressure, see the topic Home Blood Pressure Test.

If you would like more information on high blood pressure, the following resources are available:

Organizations

American Heart Association (AHA)
7272 Greenville Avenue
Dallas, TX  75231
Phone: 1-800-AHA-USA1 (1-800-242-8721)
Web Address: www.heart.org
 

Visit the American Heart Association (AHA) website for information on physical activity, diet, and various heart-related conditions. You can search for information on heart disease and stroke, share information with friends and family, and use tools to help you make heart-healthy goals and plans. Contact the AHA to find your nearest local or state AHA group. The AHA provides brochures and information about support groups and community programs, including Mended Hearts, a nationwide organization whose members visit people with heart problems and provide information and support.


CardioSmart
Web Address: www.cardiosmart.org
 

CardioSmart is an online education and support program that can be your partner in heart health. This website engages, informs, and empowers people to take part in their own care and to work well with their health care teams. It has tools and resources to help you prevent, treat, and/or manage heart diseases.

You can set health and wellness goals and track your progress with online tools. You can track your weight, waist measurement, blood pressure, and activity. You can use calculators to help you find your body mass index (BMI) and check your risk for heart problems. You can search for a cardiologist. And you can find medicine information and prepare for your next appointment. Also, you can join online communities to connect with peers and take heart-healthy challenges.

CardioSmart was designed by cardiovascular professionals at the American College of Cardiology, a nonprofit medical society. Members include doctors, nurses, and surgeons.


National Heart, Lung, and Blood Institute (NHLBI)
P.O. Box 30105
Bethesda, MD  20824-0105
Phone: (301) 592-8573
Fax: (240) 629-3246
TDD: (240) 629-3255
Email: nhlbiinfo@nhlbi.nih.gov
Web Address: www.nhlbi.nih.gov
 

The U.S. National Heart, Lung, and Blood Institute (NHLBI) information center offers information and publications about preventing and treating:

  • Diseases affecting the heart and circulation, such as heart attacks, high cholesterol, high blood pressure, peripheral artery disease, and heart problems present at birth (congenital heart diseases).
  • Diseases that affect the lungs, such as asthma, chronic obstructive pulmonary disease (COPD), emphysema, sleep apnea, and pneumonia.
  • Diseases that affect the blood, such as anemia, hemochromatosis, hemophilia, thalassemia, and von Willebrand disease.

References

Citations

  1. Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (2003). Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure JNC Express (NIH Publication No. 03–5233). Bethesda, MD: U.S. Department of Health and Human Services.
  2. American Heart Association. (2005). Recommendations for blood pressure measurement in humans and experimental animals. Part 1: Blood pressure measurement in humans. AHA Scientific Statement. Hypertension, 45(1): 142–161.

Credits

By Healthwise Staff
Primary Medical Reviewer E. Gregory Thompson, MD - Internal Medicine
Specialist Medical Reviewer Stephen Fort, MD, MRCP, FRCPC - Interventional Cardiology
Last Revised March 29, 2013

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