What is a Blood Pressure Test?
A blood pressure test is a non-invasive way of checking the pressure in your arteries caused by the pumping action of your heart. Nothing is injected and no blood is taken. . It is one of the simplest and most important health checks, because high blood pressure usually causes no symptoms but can quietly raise your risk of stroke, heart attack and kidney disease.
A cuff is wrapped around your upper arm, and a device measures your pressure within a minute or so. Your blood pressure is given as two numbers, measured in millimetres of mercury (mm Hg), and written like this: 120/80.
- Systolic pressure (the top number): the pressure in your arteries when your heart beats and pushes blood out
- Diastolic pressure (the bottom number): the pressure in your arteries when your heart relaxes between beats
Understanding Your Blood Pressure Numbers
Blood pressure is usually grouped into the following ranges:
- Normal: Below 120/80 mm Hg
- Elevated: A systolic pressure of 120 to 129 mm Hg, with a diastolic pressure below 80 mm Hg
- High blood pressure (hypertension): A systolic pressure of 130 mm Hg or higher, or a diastolic pressure of 80 mm Hg or higher. Readings of 140/90 mm Hg or higher are generally considered high on most guidelines
- Low blood pressure (hypotension): Generally a reading below 90/60 mm Hg, particularly if you also have symptoms
Blood pressure goes up and down through the day and can rise with stress, pain, caffeine or a rushed visit. Your doctor will usually diagnose hypertension only after finding raised readings on more than one occasion, and will consider your overall health when deciding what your target should be.
Why Is a Blood Pressure Test Important?
High blood pressure is often called a “silent” condition because most people feel perfectly well. Over time, however, the extra strain on your arteries and organs can lead to serious problems, including:
- Stroke
- Heart attack (myocardial infarction) and heart failure
- Kidney disease
- Damage to the blood vessels in the eyes, which can affect your vision
- Narrowing and hardening of the arteries
High blood pressure can have many causes, including family history (genetics), a sedentary lifestyle, being overweight, a diet high in salt, and other conditions such as heart defects and kidney disease. In many people, no single cause is found.
Low blood pressure can make you feel tired, light-headed and dizzy, and may cause fainting. It can be caused by dehydration, certain medications, heart problems, and hormonal or endocrine conditions, such as thyroid problems. Not everyone with low blood pressure has a medical problem, but if you have symptoms, it is worth having it checked.
Why this matters in Singapore
High blood pressure is common in Singapore. According to the Ministry of Health’s National Population Health Survey, about 1 in 3 Singapore residents aged 18 to 74 has hypertension. The figure was 37% in 2021 to 2022 and 33.8% in 2023 to 2024, and it has risen sharply since 2010, when it was about 1 in 5. The risk climbs steeply with age.
Many people do not know that they have it. Because high blood pressure causes no symptoms, a large number of people find out only during a health screening, or after a complication such as a stroke.
Our everyday diet plays a part. Favourite local dishes, such as noodle soups, curries, sauces, preserved and processed foods, and hawker fare, can be high in salt, and a diet high in sodium is a key risk factor for hypertension. Long working hours, stress and limited physical activity add to the risk.
Regular blood pressure checks are part of the national health screening recommendations. Singapore residents enrolled in Healthier SG may be eligible for subsidised or funded screening for hypertension, so ask your Healthier SG clinic for the current details.
Who Should Have a Blood Pressure Test?
- All adults should have their blood pressure checked regularly, even if they feel well
- People who are older, as the risk of high blood pressure rises with age
- People with a family history of high blood pressure, heart disease, stroke or kidney disease
- People who are overweight, have diabetes, high cholesterol or kidney problems
- People who smoke, drink heavily, eat a high-salt diet or do little exercise
- People who have already been diagnosed with high or low blood pressure and need to monitor it
- Women who are pregnant, as high blood pressure during pregnancy needs close monitoring
Preparing for Your Blood Pressure Test
No special preparation is needed for a blood pressure test. You do not need to fast, and you can take your medication as usual unless your doctor tells you otherwise. The following tips will help to get the most accurate reading:
- Avoid caffeine (coffee, tea and energy drinks), smoking and vigorous exercise for at least 30 minutes before the test
- Use the toilet beforehand, as a full bladder can raise your reading slightly
- Wear a short-sleeved top or sleeves that can be rolled up easily, without being tight on your upper arm
- Sit quietly and rest for about five minutes before the measurement
- Bring a list of your medications, and any home blood pressure readings if you have been monitoring at home
What Happens During a Blood Pressure Test?
- You will usually be seated, with your back supported, your feet flat on the floor and your legs uncrossed.
- Your arm is rested on a table or support at about heart level, with the palm facing up.
- An inflatable cuff is wrapped snugly around your bare upper arm, just above the elbow joint.
- The cuff is inflated quickly, either with a small hand pump or automatically, so that it tightens around your arm. You will feel a firm squeeze for a few seconds.
- The cuff is then slowly deflated, and the systolic and diastolic readings are taken.
- Please stay still and avoid talking while the reading is being taken.
Your reading may be taken a second time, or on both arms, to make sure that it is accurate. The whole test takes only a few minutes.
What Happens After a Blood Pressure Test?
- You will be told your blood pressure reading as soon as the test is over.
- Your doctor will look at your results and decide whether you need further tests or treatment, especially if your levels are dangerously high or low.
- If your reading is high, your doctor may ask you to monitor your blood pressure at home or over 24 hours, or to come back for repeat checks, before confirming a diagnosis. Blood and urine tests or a heart tracing (ECG) may also be suggested to look for the cause and to check for any effects on your organs.
- You will be given a follow-up appointment to review your results.
Seek emergency help straight away (call 995 in Singapore) if you have a very high reading (such as 180/120 mm Hg or higher) together with chest pain, severe headache, shortness of breath, weakness or numbness on one side of the body, changes in vision, or difficulty speaking.
Monitoring Your Blood Pressure at Home
Checking your blood pressure at home can give a clearer picture than a single reading at a clinic, and helps to spot “white coat” readings, which rise only in a medical setting. If your doctor recommends home monitoring:
- Choose a validated upper-arm monitor with a cuff that fits your arm well. Ask your doctor or pharmacist for advice
- Measure at the same times each day, for example in the morning before medication and in the evening
- Follow the same preparation steps as above: rest, sit properly and avoid caffeine and smoking beforehand
- Record your readings and bring the record, or your monitor, to your appointment
- Do not change or stop your medication on your own based on the readings
Keeping Your Blood Pressure Healthy
Healthy habits can help to lower blood pressure and may reduce the need for medication. They include:
- Cutting down on salt and sodium: choose fresh food, ask for less sauce and gravy, drink less of the soup in noodle dishes and look out for the Healthier Choice Symbol on packaged food
- Eating more fruit, vegetables and wholegrains
- Keeping to a healthy weight
- Being active: Aim for at least 150 minutes of moderate physical activity every week
- Limiting alcohol and not smoking
- Managing stress and getting enough sleep
- Taking your medication as prescribed if you have been given any, and going for regular check-ups
