Measuring Blood Pressure
Reviewed
Also called: Blood Pressure Reading, Blood Pressure Test, Blood Pressure Screening, Sphygmomanometry
A blood pressure measurement is a test that measures the force of blood against artery walls as the heart pumps. It is used to screen for high blood pressure (hypertension) and sometimes to check for low blood pressure (hypotension). The test is quick, noninvasive, and often part of a routine checkup.
Specimen: Not applicable
Urgent safety information
Seek immediate medical attention or call 911 if your blood pressure is over 180/120 mmHg and you have chest pain, shortness of breath, back pain, numbness or weakness, trouble speaking, or vision changes. Also seek emergency care if you have symptoms of extremely low blood pressure such as confusion, a weak and rapid pulse, or cold skin.
Why this test may be ordered
- To screen for high blood pressure during regular checkups
- To monitor how well blood pressure medicines are working
- To check blood pressure before medical or surgical procedures
- To evaluate symptoms of low blood pressure such as dizziness or fainting
- To assess fitness for sports or strenuous activities
Preparation and collection
Avoid exercise, alcohol, tobacco, and food or drinks containing caffeine for at least 30 minutes before the test. Empty your bladder before the test. Tell your provider about any medicines you take, as some may affect results.
You will sit in a chair with feet flat on the floor and your arm resting on a table so it is level with your heart. A blood pressure cuff is wrapped snugly around your upper arm, just above the elbow. The cuff is inflated to block blood flow briefly, then slowly deflated while the provider measures pressure manually with a stethoscope or using an automated device. The test takes about one minute.
You may have a little discomfort when the blood pressure cuff inflates and squeezes your arm, but this feeling only lasts for a few seconds.
Understanding results
Your blood pressure reading has two numbers: systolic (pressure when the heart beats) and diastolic (pressure when the heart rests between beats). Readings are grouped into categories. A single high reading does not mean you have high blood pressure; your provider usually diagnoses high blood pressure only after two or more high readings on different days, considering your medical and family history.
- Normal: Systolic less than 120 and Diastolic less than 80: Your blood pressure is in the normal range. Limitation: This is a screening result; it does not rule out future changes in blood pressure. Next step: Continue with routine checkups as recommended by your provider.
- Elevated: Systolic 120-129 and Diastolic less than 80: Your blood pressure is higher than normal but not yet in the high blood pressure range. Limitation: This is a screening result; it does not confirm a diagnosis of hypertension. Next step: Your provider may recommend lifestyle changes such as a healthy diet, physical activity, and weight management to help lower your blood pressure.
- High Blood Pressure Stage 1: Systolic 130-139 or Diastolic 80-89: Your blood pressure is in the stage 1 high blood pressure range. Limitation: This is a screening result; a diagnosis of high blood pressure usually requires two or more high readings on different days. Next step: Your provider may recommend lifestyle changes and possibly medicines to control your blood pressure. You may also be advised to monitor your blood pressure at home.
- High Blood Pressure Stage 2: Systolic 140 or higher or Diastolic 90 or higher: Your blood pressure is in the stage 2 high blood pressure range. Limitation: This is a screening result; a diagnosis of high blood pressure usually requires two or more high readings on different days. Next step: Your provider will likely recommend lifestyle changes and medicines to control your blood pressure. Home monitoring may be advised.
- A single high reading does not mean you have high blood pressure; diagnosis usually requires two or more high readings on different days.
- Nervousness about having blood pressure taken at a provider's office (white coat syndrome) can cause a temporary rise in blood pressure, making results less accurate.
- The test measures pressure at one moment and can vary based on activity, stress, or time of day.
- For children under 13, results are compared to age-, sex-, and height-specific norms, which may not be directly comparable to adult categories.
What to do next
If you are diagnosed with high blood pressure, your provider may recommend lifestyle changes such as regular physical activity, maintaining a healthy weight, eating a heart-healthy diet (e.g., DASH eating plan), reducing salt intake, limiting alcohol, quitting smoking, managing stress, and getting enough sleep. You may also be advised to check your blood pressure at home using an automated monitor. For low blood pressure, treatments may include medicines and dietary changes. Always follow your provider's guidance.
- What is my blood pressure reading and what category does it fall into?
- How often should I have my blood pressure checked?
- Do I need to monitor my blood pressure at home? If so, what type of monitor should I use?
- What lifestyle changes can help me manage my blood pressure?
- What symptoms should prompt me to seek emergency care?