A Beginner’s Guide to Blood Pressure Monitoring
High blood pressure is common, usually has no symptoms and is a leading cause of heart attack and stroke. The only way to know your blood pressure is to measure it. Home monitoring has become a routine part of care because it is simple, inexpensive and gives a fuller picture than occasional clinic readings.
Key points
- Blood pressure is recorded as two numbers, systolic over diastolic, in millimeters of mercury (mm Hg).
- An automatic upper arm monitor with the right cuff size is the standard choice for home use.
- Measure at the same times each day, seated and rested, and share the record with your doctor.
What blood pressure is
Blood pressure is the force of blood pushing against the walls of your arteries as the heart pumps. It rises and falls through the day with activity, stress, sleep and posture. When it stays high over time, it damages blood vessels and makes the heart work harder.
Why monitor at home
The CDC notes that high blood pressure usually has no warning signs, so many people do not know they have it. Home monitoring, which doctors call self-measured blood pressure monitoring, helps to:
- confirm a diagnosis when clinic readings are borderline;
- show whether treatment and lifestyle changes are working;
- detect “white coat” effects, where readings are higher in a clinic than at home, and the opposite pattern, where clinic readings look normal but home readings are high;
- involve you directly in your own care.
Understanding the numbers
A reading such as 118/76 mm Hg has two parts.
- Systolic (top number): pressure when the heart beats.
- Diastolic (bottom number): pressure when the heart rests between beats.
The American Heart Association classifies adult readings as:
- Normal: below 120 and below 80
- Elevated: 120 to 129 and below 80
- High blood pressure, stage 1: 130 to 139 or 80 to 89
- High blood pressure, stage 2: 140 or higher or 90 or higher
Only a healthcare professional can diagnose high blood pressure, usually from several readings on separate occasions.
What you need
- An automatic upper arm monitor. These inflate the cuff and display the result at the press of a button. See our Automatic Upper Arm Blood Pressure Monitor.
- A cuff that fits. Measure around the middle of your upper arm and check the range printed on the cuff.
- A way to record readings, such as a log book or the monitor’s memory.
How to take a reading
The CDC recommends these steps:
- Do not eat or drink anything for 30 minutes beforehand, and empty your bladder.
- Sit in a comfortable chair with your back supported for at least five minutes.
- Put both feet flat on the ground and keep your legs uncrossed.
- Rest your arm with the cuff on a table at chest height.
- Make sure the cuff is snug but not too tight, against bare skin.
- Do not talk while the measurement is taken.
- Take at least two readings, one or two minutes apart.
When to measure
Your doctor will tell you how often. A common approach is to measure at the same times each day, such as morning and evening, for a set period before an appointment. Consistency matters more than frequency.
Recording results
Write down the date, time, both numbers and your pulse. Add notes about anything unusual, such as a missed medicine or a stressful day. Take the record, and occasionally the monitor itself, to appointments.
What home monitoring cannot do
- It does not replace regular visits to your doctor.
- It should not lead you to change or stop medicines yourself.
- A single high reading is not a diagnosis.
When to seek help urgently
If a reading is higher than 180 systolic or higher than 120 diastolic, wait a few minutes and measure again. If it is still that high, contact your healthcare professional straight away. If you also have chest pain, shortness of breath, back pain, numbness, weakness, changes in vision or difficulty speaking, call 911.
The bottom line
Blood pressure monitoring is a small habit with real value. With a suitable monitor, good technique and a simple record, you give your doctor the information needed to look after your heart. See monitors and accessories in our heart and blood pressure department.
Sources
- Centers for Disease Control and Prevention. Measuring Your Blood Pressure.
- Centers for Disease Control and Prevention. About High Blood Pressure.
- American Heart Association. Understanding Blood Pressure Readings.
- National Heart, Lung, and Blood Institute. High Blood Pressure.
More heart & blood pressure guides
How to Store and Care for Medical Monitoring Devices
Keep blood pressure monitors, thermometers, pulse oximeters and scales accurate with correct cleaning, storage, battery care and periodic checks.
How to Choose a Digital Blood Pressure Monitor
Look for a validated, automatic upper arm monitor with the right cuff size, a clear display and memory. A buyer's checklist for home blood…
Understanding Home Heart Monitoring Devices
Blood pressure monitors, heart rate trackers, personal ECG devices, pulse oximeters and scales: what each home heart monitoring device measures and its limits.