What is blood pressure?
Blood pressure is the measurement of the pressure or force of blood inside your arteries. Each time your heart beats, it pumps blood into arteries that carry blood throughout your body. This happens 60 to 100 times a minute, 24 hours a day. Arteries deliver oxygen and nutrients to your whole body so it can function.
Blood pressure vs. heart rate
Both of these have to do with your heart, but they’re two different things. Blood pressure is how powerfully your blood travels through your blood vessels. Heart rate is the number of times your heart beats in one minute.
An increase in heart rate doesn’t mean your blood pressure is going up, too. The only way to know your blood pressure is to measure it with a blood pressure cuff and gauge.
Why blood pressure fluctuates
Your blood pressure doesn’t stay the same at all times. It changes based on what you’re doing. When you’re exercising or excited, your blood pressure goes up. When you’re resting, your blood pressure is lower.
Your blood pressure can also change because of your:
- Medications you take.
- Changes in position.
Why blood pressure matters
High blood pressure — the “silent killer” — usually has no symptoms. It can damage your heart, kidneys and brain before you know anything is wrong.
High blood pressure is a major risk factor for cardiovascular disease. Without treatment, high blood pressure can cause:
- Transient ischemic attack (TIA).
- Heart attack.
- Enlarged heart.
- Heart failure.
- Peripheral artery disease.
- Kidney disease.
- Broken blood vessels in your eyes.
Who is at risk of getting high blood pressure?
Your risk of high blood pressure is higher if you:
- Have a family history of high blood pressure, cardiovascular disease or diabetes.
- Are Black.
- Are age 60 or older.
- Have high cholesterol.
- Use oral contraceptives (birth control pills).
- Have obesity.
- Have diabetes.
- Use tobacco products.
- Don’t exercise.
- Have eat a high salt diet.
When is blood pressure checked?
Your healthcare provider should check your blood pressure at every annual checkup if your blood pressure is normal. If your blood pressure readings are high at your appointments, your provider may ask you to check your blood pressure at home anywhere from several times a day to once a week.
You should take blood pressure readings at the same time of day each time. You can take two or three readings one after the other, as long as you wait one minute before the next one. When you’re done, figure out the average of the two or three readings you took.
Your provider may ask you to wear a blood pressure monitor for 24 hours. The monitor is usually set to take blood pressure every 15 to 30 minutes while you do your normal activities.
What treatments are available for patients with high blood pressure?
High blood pressure is a major risk factor for cardiovascular disease. Without treatment, you can have a transient ischemic attack (TIA) or stroke, heart attack, enlarged heart, heart failure, peripheral vascular disease (such as poor circulation and pain in your legs), aneurysms, kidney disease, and broken blood vessels in your eyes. Treatment includes making changes recommended by your healthcare provider.
Diet and lifestyle changes:
- Reach and stay at your ideal body weight
- Get regular exercise
- Eat a well-balanced, heart-healthy diet that is low in salt, fat and cholesterol, and contains lots of fresh fruits and vegetables. Your diet is an important part of managing your blood pressure. The Dietary Approaches to Stop Hypertension (DASH) eating plan and limiting sodium (salt) help manage blood pressure. Ask your doctor to refer you to a dietitian for a more personalized eating plan.
- Having no more than two drinks containing alcohol per day (for most men) and no more than one drink per day for women and lighter-weight men. One drink is considered to be 12 ounces of beer or wine cooler, 5 ounces of wine or 1.5 ounces of 80-proof liquor.
- Manage stress and anger.
- Avoid all tobacco and nicotine products.
- Other lifestyle changes, such as managing lipid levels (LDL, cholesterol, triglycerides) and managing other health conditions, such as diabetes.
Medications and follow-up care:
- Take all medications as prescribed. Do not stop or start taking any medication without talking to your doctor. Blood pressure medication does not keep working after you stop taking it.
- Some over-the-counter medications, such as decongestants, can change the way your blood pressure medication works.
- Keep all follow-up appointments so your doctor can monitor your blood pressure, make any needed changes to your medications and help manage your risk of cardiovascular disease.
Your doctor may ask you to record your blood pressure at home. Follow your doctor’s instructions for recording your blood pressure.
How do I prepare for a blood pressure measurement?
- Wait 30 minutes to measure your blood pressure if you just smoked, exercised or had a cup of coffee.
- Go to the bathroom and pee until your bladder is empty.
- Roll up your sleeve so you don’t put the cuff over your shirt sleeve.
- Sit for at least five minutes without talking.
- Sit up straight with your feet flat on the floor. Don’t cross your legs.
- Rest your arm on a table in front of you so your arm is at heart level.
How blood pressure is measured
To measure your blood pressure manually, your provider will:
- Wrap a special cuff (connected to a gauge or sphygmomanometer) around your upper arm (above your elbow).
- Inflate the cuff to make it tight around your arm. They’ll squeeze a ball connected to the cuff to do this. This briefly stops blood flow in your brachial artery by squeezing it. The gauge should say 200 mmHg at this time.
- Deflate the cuff (with a valve attached to the cuff) while using a stethoscope to listen to your blood going through your brachial artery. Deflating the cuff makes the gauge needle start to come down.
- Listen for when a pulse starts and look at the number on the gauge at that time. That’s the systolic number.
- Open the valve to loosen the blood pressure cuff so it stops squeezing your brachial artery.
- Look at the gauge reading when the cuff deflates and they hear (through the stethoscope) blood flowing again. This is the diastolic number.
You or your provider can use a blood pressure monitor to check your blood pressure automatically.
What should I expect after the blood pressure test?
If you’re nervous when you go to your appointment, you could have a false high blood pressure reading. This is called “white coat syndrome.” If this happens, your healthcare provider may ask you to use a blood pressure monitor to check your blood pressure throughout the day. You can bring a record of your blood pressure readings to your appointments.
Are there side effects to a blood pressure measurement?
The cuff around your arm gets very tight when it’s inflated for a blood pressure measurement. However, it’s only tight for a short time before it gets comfortable again.
Results and Follow-Up
What type of results do you get?
Your blood pressure reading has two measurements:
- Systolic blood pressure (the top/first number): This is the pressure in your arteries when your heart is beating and sending blood into your arteries.
- Diastolic blood pressure (the bottom/second number): This is the pressure in your arteries when your heart is at rest between heartbeats.
Providers give the measurements as millimeters of mercury (mm Hg). They started using these measurements when instruments to measure blood pressure contained mercury.
What is normal blood pressure?
Normal blood pressure is <120/<80 millimeters of mercury.
Elevated blood pressure is 120-129/<80 millimeters of mercury. People with blood pressure readings in this category can develop worse blood pressure if they don’t do something to improve it.
What blood pressure is too high?
If your top number is ever 180 or higher and/or your bottom number is ever 120 or higher, get emergency medical treatment or have someone take you to the hospital right away. This is a hypertensive crisis.
During a hypertensive crisis, you may experience:
- Shortness of breath.
- Chest pain.
- Difficulty with being able to see or talk.
- Pain in your back.
- Weakness or numbness.
Higher blood pressure ranges mean you may have stage 1 or 2 hypertension (high blood pressure).
- Stage 1 hypertension is 130-139 (top number) or 80-89 (bottom number).
- Stage 2 hypertension is 140 or higher (top number) or 90 or higher (bottom number).
When your blood pressure readings are in stage 1 or stage 2, your provider will ask you to make lifestyle changes and take blood pressure medicine.
What blood pressure is too low?
A reading below 90/60 millimeters of mercury is a low blood pressure reading. This can be a normal reading for some people who always have low blood pressure. For other people, low blood pressure means something’s wrong. They may not have enough blood flowing to their major organs.
Which blood pressure number is more important?
Your healthcare provider can use the top or bottom number to diagnose you with high blood pressure. However, they usually focus more on the top number as a risk factor for heart disease if you’re older than 50.
As you get older, the top blood pressure number rises because your arteries get stiff and collect plaque (fat and cholesterol) over time.
When should I know the results of the blood pressure measurement?
You’ll know your blood pressure reading right away, but your provider needs two or more readings (on different days) to determine if you have high blood pressure. They may make another appointment to check your blood pressure again on another day.
When should I call my doctor?
Contact your healthcare provider if your blood pressure reading at home is lower or higher than normal. Call 911 if your reading is 180/120 millimeters of mercury or even if only one of those numbers is that high.
A note from Cleveland Clinic
Even though you may not feel any symptoms, your blood pressure could be high. It’s important to check your blood pressure regularly so you know if you’re in the normal range. If you have high blood pressure, keep taking the medications your provider prescribed. Don’t stop or start taking them without talking to your provider. Blood pressure medication doesn’t keep working after you stop taking it. Keep all follow-up appointments so your provider can monitor your blood pressure, make any needed changes to your medications and help manage your risk of cardiovascular disease.
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