Why Check Your Pressure?

The importance of home blood pressure monitoring

High blood pressure (hypertension) affects over 900 million people worldwide and is one of the leading causes of death from cardiovascular disease (CVD). Research indicates that at-home self-measurement is beneficial in several ways:

• It provides more blood pressure measurements within a limited period of time.
• It serves as an incentive for you to see results immediately and have more control over your treatment.
• Keeping a log of measurements over time can assist your healthcare provider in adjusting your medication(s), diagnosing and preventing problems.
• Being able to check your blood pressure in a variety of situations (at work, for example) may give a clearer picture of your overall blood pressure health.
• It can help detect "white coat hypertension," an elevation in blood pressure which is brought on by the anxiety of being in the doctor's office.
• It enables those with normal blood pressure to verify their health and be proactive.

Blood pressure is the force of the blood pushing against the walls of the arteries. Each time the heart beats (about 60 to 70 times a minute at rest), it pumps out blood into the arteries. Blood pressure is at its highest when the heart beats, pumping the blood (systolic pressure). When the heart is at rest between beats, your blood pressure falls (diastolic pressure). High blood pressure is a blood pressure reading of 140/90 mmHg or higher. If you have kidney disease or diabetes, the ranges may be different.

Blood pressure ranges:

Source: National Heart, Lung & Blood Institute, National Institutes of Health

Getting an accurate reading

If you are using an arm model, you will get an accurate reading only if the cuff fits properly. A too-small cuff can give falsely high readings; a too-large cuff can give readings that are falsely low. Individuals with very large or very thin arms may not be able to use a regular-sized cuff, however many manufacturers either offer models with different sized cuffs, or offer different sized cuffs as an optional accessory.

To ensure appropriate fit, the cuff should fit smoothly and snugly (you should be able to fit a fingertip under the cuff) around the upper part of your arm. The bottom edge of the cuff should be about one inch above the elbow crease. To size a cuff, measure your arm's circumference halfway between your shoulders and elbow while standing with your arm hanging at your side. Small = 7 to 9 inches (18 to 22 cm); Medium = 9 to 13 inches (22 to 32 cm); Large = 13 or more inches (32 cm or more).

Here are some hints to help you get accurate blood pressure readings:

• Avoid exercise, caffeine, alcohol and tobacco for about 30 minutes.
• Use the bathroom first.
• Rest for about 15 minutes and avoid conversation.
• Sit comfortably with your back supported, legs and ankles uncrossed.
• Remove anything that may interfere with the measurement (jewelry, watch, etc.).

Arm position is critical for accurate readings. Sit upright with your arm slightly bent at the elbow. Rest your forearm on a flat surface at the same level as your heart, extended straight forward at heart level.

Blood pressure can vary by 30 to 50 mmHg throughout the course of a day, and can be influenced by diet, activity level, emotions, room temperature, background noise, muscle tension and body position. You'll get the best results if you take the measurements at the same time and under the same conditions each day. Early morning and evening readings are usually the most helpful. If you have work-related stress that affects your blood pressure, be sure to take and record measurements on both work and non-work days.

Experts recommend taking at least two readings at intervals of several minutes or longer (this gives your arm's brachial artery enough time to recover from being squeezed by the tight cuff) and recording the average.

Regardless of what blood pressure monitor style you use, there is usually a small difference between blood pressure readings in alternate arms, so you should stay consistent with which arm, wrist or finger you use when monitoring for best results. According to the Mayo Foundation for Medical Education and Research, the highest reading is typically the truest.