How to measure your blood pressure at home

High blood pressure rarely causes symptoms, which is why it is often called a silent condition. Measuring it at home gives your doctor a far better picture than a single reading in a busy clinic, where many people’s numbers run high simply because they are nervous.

Choose the right monitor

• Pick an automatic upper-arm monitor; wrist and finger devices are less reliable.
• Make sure the cuff fits: it should wrap around your bare upper arm with room for one finger underneath. Large arms need a large cuff.
• Look for a model that has been clinically validated, and bring it to your next appointment so we can check it against ours.

Get ready

Small things can change a reading by 10 points or more. For half an hour beforehand, avoid:

• coffee, tea and energy drinks
• smoking and exercise
• a full bladder – go to the toilet first

Then sit quietly for five minutes before you start.

Take the reading

1. Sit in a chair with your back supported and both feet flat on the floor. Do not cross your legs.
2. Rest your arm on a table so the cuff is level with your heart.
3. Put the cuff on bare skin, about two finger-widths above the bend of your elbow.
4. Stay still and do not talk while the monitor works.
5. Take two readings a minute apart and write both down.

Measure in the morning before breakfast and any medicines, and again in the evening. Doing this for seven days before an appointment gives your doctor a reliable average.

Understanding the numbers

The top number (systolic) is the pressure when your heart beats; the bottom number (diastolic) is the pressure between beats. For most adults, a home average below 120/80 is considered normal. Your doctor will set the right target for you, which may be different if you have diabetes, kidney disease or other conditions.

“One high reading is not a diagnosis. A week of careful home readings tells us much more than any single number.” — Dr. Samuel Okafor, Head of Internal Medicine

Keep a simple log

Write down the date, the time, both readings and anything unusual – a poor night’s sleep, a missed tablet, a stressful day. Many monitors store readings, but a written log is easier to bring to an appointment. Your doctor will usually ignore the first day’s readings and average the rest, so do not worry about one high number.

When to call

Contact your doctor if your readings are consistently above your target. Call your local emergency number if a reading is very high and you also have chest pain, severe headache, confusion, weakness on one side or trouble speaking.

Keeping your numbers down

• Use less salt, and check labels on bread, sauces and ready meals.
• Fill half your plate with vegetables and fruit.
• Move for at least 150 minutes a week.
• Keep alcohol within recommended limits.
• Take your medicines every day, even when you feel well.

This article is general information, not medical advice. Ask your doctor what your blood pressure target should be.