What Is Blood Pressure?
2022-07-21
By Cherie Berkley
Blood pressure (BP) is the pressure of circulating blood on the walls of arteries. Healthcare providers use BP readings to help evaluate cardiovascular health.
BP is measured as a systolic pressure (the top number) and a diastolic pressure (the bottom number). The normal range for systolic BP in adults is less than 120 millimeters of mercury (mm Hg), and the normal range for diastolic BP is less than 80 mm Hg—for a normal BP reading of less than 120/80 mm Hg.
Systolic Vs. Diastolic Blood Pressure
Systolic BP is the amount of pressure exerted against your artery walls as your heart contracts, pushing blood into the arteries. Diastolic BP measures the lowest pressure in your arteries as your heart maximally relaxes.
Blood pressure readings for adults fall into five categories:
Blood Pressure Stages
Blood Pressure Status Systolic Diastolic
Normal 120 80
Elevated 130-139 or 80-89
Hypertension Stage 1 140 or higher and/or 90 or higher
Hypertension Stage 2 140 or higher or 90 or higher
Hypertension Crisis 180 or higher and/or Higher than 120
High or Low Blood Pressure
Hypertension is when your BP is above normal. When BP is too high for too long, it can slowly and significantly harm your health. Often, people with hypertension have no symptoms, and thus may be unaware they have high BP.
Hypotension is when your BP is too low or below normal. It can cause fainting, dizziness, and fatigue. Low BP typically only presents a problem when it's linked to symptoms.
According to the American Heart Association, there is no specific number at which day-to-day BP is considered too low.Within certain limits, it is ideal to keep your BP on the low side, as long as you aren't experiencing symptoms of low BP.
Symptoms of Abnormal Blood Pressure
You can even have hypertension for years without any symptoms.High BP can damage organs and arteries. This is why hypertension is called the “silent killer.”
Symptoms may appear, but only after BP has reached a crisis stage. At this stage, you may experience severe chest pain, severe headaches with blurred vision, nausea and vomiting, shortness of breath, and/or seizures.Often, high BP is identified during a routine physical exam.
Hypotension can cause symptoms, including:
Fainting
Dizziness or lightheadedness
Dehydration and excessive thirst
Rapid, shallow breathing
Blurred vision
Cold, clammy, pale skin
Depression
Nausea
Fatigue
Diminished concentration
How Blood Pressure Is Evaluated
A healthcare professional will take your BP with a pressure-measuring gauge that's attached to an inflatable cuff that's placed around your arm. It is important to have a proper fitting arm cuff to get a correct reading. Ideally, your BP should be measured in both arms.
Healthcare providers confirm a diagnosis of hypertension over a series of separate appointments. They will take two to three readings at each visit before making a hypertension diagnosis.
Your practitioner may also ask you to check your BP at home and keep a log of the readings or may ask you to wear a 24 hr BP monitor (known as ambulatory BP monitoring). They will do this for two reasons—people can have varying BP readings throughout the day, and it can be unusually elevated at healthcare providers’ visits because of anxiety (white coat hypertension).
Hypotension is diagnosed based on BP measurements and symptoms.
Additionally, your evaluation of hypertension and hypotension may include:
Blood tests: These can provide information about your health and can identify underlying diseases.
Electrocardiogram (ECG): The test provides information about your heart function and can be used to detect irregularities in your heart rate and rhythm.
Tilt table test: If you experience low BP, a tilt table test may determine how your body responds when changing position.
Blood pressure (BP) is the pressure of circulating blood on the walls of arteries. Healthcare providers use BP readings to help evaluate cardiovascular health.
BP is measured as a systolic pressure (the top number) and a diastolic pressure (the bottom number). The normal range for systolic BP in adults is less than 120 millimeters of mercury (mm Hg), and the normal range for diastolic BP is less than 80 mm Hg—for a normal BP reading of less than 120/80 mm Hg.
Systolic Vs. Diastolic Blood Pressure
Systolic BP is the amount of pressure exerted against your artery walls as your heart contracts, pushing blood into the arteries. Diastolic BP measures the lowest pressure in your arteries as your heart maximally relaxes.
Blood pressure readings for adults fall into five categories:
Blood Pressure Stages
Blood Pressure Status Systolic Diastolic
Normal 120 80
Elevated 130-139 or 80-89
Hypertension Stage 1 140 or higher and/or 90 or higher
Hypertension Stage 2 140 or higher or 90 or higher
Hypertension Crisis 180 or higher and/or Higher than 120
High or Low Blood Pressure
Hypertension is when your BP is above normal. When BP is too high for too long, it can slowly and significantly harm your health. Often, people with hypertension have no symptoms, and thus may be unaware they have high BP.
Hypotension is when your BP is too low or below normal. It can cause fainting, dizziness, and fatigue. Low BP typically only presents a problem when it's linked to symptoms.
According to the American Heart Association, there is no specific number at which day-to-day BP is considered too low.Within certain limits, it is ideal to keep your BP on the low side, as long as you aren't experiencing symptoms of low BP.
Symptoms of Abnormal Blood Pressure
You can even have hypertension for years without any symptoms.High BP can damage organs and arteries. This is why hypertension is called the “silent killer.”
Symptoms may appear, but only after BP has reached a crisis stage. At this stage, you may experience severe chest pain, severe headaches with blurred vision, nausea and vomiting, shortness of breath, and/or seizures.Often, high BP is identified during a routine physical exam.
Hypotension can cause symptoms, including:
Fainting
Dizziness or lightheadedness
Dehydration and excessive thirst
Rapid, shallow breathing
Blurred vision
Cold, clammy, pale skin
Depression
Nausea
Fatigue
Diminished concentration
How Blood Pressure Is Evaluated
A healthcare professional will take your BP with a pressure-measuring gauge that's attached to an inflatable cuff that's placed around your arm. It is important to have a proper fitting arm cuff to get a correct reading. Ideally, your BP should be measured in both arms.
Healthcare providers confirm a diagnosis of hypertension over a series of separate appointments. They will take two to three readings at each visit before making a hypertension diagnosis.
Your practitioner may also ask you to check your BP at home and keep a log of the readings or may ask you to wear a 24 hr BP monitor (known as ambulatory BP monitoring). They will do this for two reasons—people can have varying BP readings throughout the day, and it can be unusually elevated at healthcare providers’ visits because of anxiety (white coat hypertension).
Hypotension is diagnosed based on BP measurements and symptoms.
Additionally, your evaluation of hypertension and hypotension may include:
Blood tests: These can provide information about your health and can identify underlying diseases.
Electrocardiogram (ECG): The test provides information about your heart function and can be used to detect irregularities in your heart rate and rhythm.
Tilt table test: If you experience low BP, a tilt table test may determine how your body responds when changing position.
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