A blood pressure test is done to diagnose elevated blood pressure. A blood pressure test may be done as a part of a routine health checkup or as a screening for high blood pressure (hypertension).
Blood pressure is measured in millimeters of mercury (mm Hg). A blood pressure measurement has two numbers:
- The top number (systolic) is the pressure of the blood flow when the heart muscle squeezes (contracts), pumping blood.
- The bottom number (diastolic) is the pressure in the arteries measured between heartbeats.
Elevated blood pressure is a measurement of 120 to 129 mm Hg and a bottom number below (not above) 80 mm Hg.
A diagnosis of elevated blood pressure is based on the average of two or more blood pressure readings. The measurements should be taken on separate occasions in the same way. The first time your blood pressure is checked, it should be measured in both arms to determine if there's a difference. After that, the arm with the higher reading should be used.
A longer blood pressure monitoring test can be done to check blood pressure at regular times over six or 24 hours. This is called ambulatory blood pressure monitoring. However, the devices used for the test aren't available in all medical centers. Check with your insurer to see if ambulatory blood pressure monitoring is a covered service.
Your provider might also suggest that you check your blood pressure at home. Home blood pressure monitors are available at local stores and pharmacies. Some devices store the measurements in its memory.
If you have elevated or high blood pressure, your health care provider may do blood and urine tests to check for conditions that can cause it. Tests may include:
- Complete blood count
- Cholesterol test (lipid profile)
- Blood sugar (glucose) test
- Kidney function tests
- Thyroid function tests
Other tests may also be done.
You might also have an electrocardiogram (ECG/EKG) to check how the heart is beating. An ECG is quick and painless. During an ECG, sensors (electrodes) are attached to the chest and sometimes to the arms or legs. Wires connect the sensors to a machine, which prints or displays results.
Healthy lifestyle changes are recommended for anyone with elevated or high blood pressure.
If you have elevated blood pressure and diabetes, kidney disease or heart disease, your provider might also recommend blood pressure medication.
If you have elevated blood pressure but don't have any heart disease risk factors, the benefits of medication are less clear.
Treatment for stage 1 or stage 2 hypertension usually includes blood pressure medications and healthy lifestyle changes.
Lifestyle and home remedies
As blood pressure increases, so does the risk of heart disease. That's why it's so important to control elevated blood pressure. The key is a commitment to healthy lifestyle changes. Try these tips:
- Eat healthy foods. Eat a healthy diet. Try the Dietary Approaches to Stop Hypertension (DASH) diet. Choose fruits, vegetables, whole grains, poultry, fish and low-fat dairy foods. Get plenty of potassium from natural sources, which can help lower blood pressure. Eat less saturated fat and trans fat.
- Use less salt (sodium). Processed meats, canned foods, commercial soups, frozen dinners and certain breads can be hidden sources of salt. Check food labels for the sodium content. Aim to limit sodium by at least 1,000 milligrams (mg) a day. A lower sodium intake — 1,500 mg a day or less — is ideal for most adults.
- Manage weight. Losing weight if you're overweight or have obesity can help control blood pressure and lower the risk of complications. Ask your health care provider what weight is best for you. In general, blood pressure drops by about 1 mm Hg with each kilogram (about 2.2 pounds) of weight lost. In people with high blood pressure, the drop in blood pressure may be even more significant per kilogram of weight lost.
- Increase physical activity. Regular exercise keeps the body healthy. It can lower blood pressure, ease stress, manage weight and reduce the risk of chronic health conditions. Aim to get at least 150 minutes a week of moderate aerobic activity or 75 minutes a week of vigorous aerobic activity, or a combination of the two.
- Limit alcohol. If you choose to drink alcohol, do so in moderation. For healthy adults, that means up to one drink a day for women and up to two drinks a day for men.
- Don't smoke. Tobacco injures blood vessel walls and speeds up the process of hardening of the arteries. If you smoke, ask your care provider for strategies to help you quit.
- Manage stress. Find ways to help reduce emotional stress. Getting more exercise, practicing mindfulness and connecting with others in support groups are some ways to reduce stress.
Preparing for your appointment
If you think you may have elevated or high blood pressure, make an appointment with your family care provider to have your blood pressure checked.
No special preparations are necessary. To get an accurate blood pressure reading, avoid caffeine, exercise and tobacco for at least 30 minutes before the test.
Because some medications can raise blood pressure, bring a list of all medications, vitamins and other supplements you take and their doses to your medical appointment. Don't stop taking any prescription medications that you think might affect your blood pressure without your provider's advice.
Here's some information to help you get ready for your appointment.
What you can do
Make a list of:
- Your symptoms, if you have any, even if they seem unrelated to the reason you scheduled the appointment, and when they began
- Important personal information, including any family history of high blood pressure, high cholesterol, heart disease, stroke or diabetes, and any major stresses or recent life changes
- Write down questions to ask your provider.
For elevated blood pressure, questions to ask your health care provider include:
- What tests do I need?
- Do I need to take medication?
- What foods should I eat or avoid?
- What's an appropriate level of physical activity?
- How often do I need to have my blood pressure checked?
- Should I check my blood pressure at home?
- I have these other health conditions. How can I best manage them together?
- Are there brochures or other printed material that I can have? What websites do you recommend?
Don't hesitate to ask other questions.
What to expect from your doctor
Your health care provider is likely to ask you a number of questions, including:
- What are your diet and exercise habits like?
- Do you drink alcohol? How many drinks do you have in a week?
- Do you smoke?
- When did you last have your blood pressure checked? What was the result?