What is normal blood pressure?

Published by Health Professional

on Tuesday, March 14th 2023


  • General
  • Heart Diseases
  • Weight Control
  • Blood pressure measures the force exerted by blood against the walls of blood vessels as it circulates through the body. It is an important vital sign that helps to evaluate cardiovascular health. 

    High blood pressure or hypertension is a significant risk factor for several health conditions, such as heart disease, stroke, and kidney disease. Therefore, it is essential to understand what constitutes normal blood pressure, how to monitor it, and the potential risks of abnormal readings.

    Definition of Blood Pressure

    Blood pressure is measured in systolic pressure (the top number) and diastolic pressure (the bottom number). 

    Systolic pressure measures the force when the heart contracts, while diastolic pressure measures the force when the heart is relaxed between beats. Blood pressure is expressed in millimeters of mercury (mmHg).

    Importance of Monitoring Blood Pressure

    Monitoring blood pressure is essential to maintaining good health, as high blood pressure often has no symptoms but can still cause significant damage to blood vessels and organs such as the heart, kidneys, and brain. 

    Consistent blood pressure monitoring can alert individuals to potential issues early and allow them to take corrective measures. Blood pressure measurements can be taken at home using a blood pressure monitor or in a healthcare provider’s office.

    Explanation of Normal Blood Pressure

    According to the World Health Organization (WHO), optimal blood pressure is below 120 mmHg systolic and 80 mmHg diastolic. Blood pressure values between 120-139 mmHg systolic and 80-89 mmHg diastolic are considered high-normal. 

    The blood pressure range between 140-159 mmHg systolic and 90-99 mmHg diastolic is classified as mild hypertension, while moderate hypertension occurs when the systolic pressure is between 160-179 mmHg and the diastolic pressure is between 100-109 mmHg. 

    Severe hypertension occurs when the systolic pressure is greater than or equal to 180 mmHg and the diastolic pressure is greater than or equal to 110 mmHg. These values may differ slightly between organizations and health professionals, but the general range for normal blood pressure is consistent.

    Normal Blood Pressure Range

    Systolic Blood Pressure Range for Adults:

    • Optimal: less than 120 mmHg
    • High-Normal: 120-139 mmHg
    • Mild Hypertension: 140-159 mmHg
    • Moderate Hypertension: 160-179 mmHg
    • Severe Hypertension: greater than or equal to 180 mmHg

    Diastolic Blood Pressure Range for Adults:

    • Optimal: less than 80 mmHg
    • High-Normal: 80-89 mmHg
    • Mild Hypertension: 90-99 mmHg
    • Moderate Hypertension: 100-109 mmHg
    • Severe Hypertension: greater than or equal to 110 mmHg

    How Age Affects Blood Pressure Readings

    Blood pressure can increase with age due to several factors, such as decreased elasticity of blood vessels and increased plaque buildup in arteries. Therefore, blood pressure ranges are often adjusted for age to reflect these changes.

    Abnormal Blood Pressure Readings

    Elevated Blood Pressure Range:

    • Systolic: 120-129 mmHg
    • Diastolic: less than 80 mmHg

    Blood pressure readings are critical to measuring one’s overall health, and abnormal readings may indicate underlying health issues. Abnormal blood pressure readings are classified as either elevated blood pressure, stage 1 hypertension, or stage 2 hypertension.

    Elevated blood pressure is a category that indicates a higher risk of developing hypertension in the future. This reading is defined as a systolic blood pressure ranging from 120 to 129 mm Hg and diastolic blood pressure less than 80 mm Hg.

    Stage 1 hypertension

    It is defined as a systolic blood pressure ranging from 130 to 139 mm Hg or a diastolic blood pressure ranging from 80 to 89 mm Hg. 

    Stage 2 hypertension 

    It is classified as a systolic blood pressure greater than or equal to 140 mm Hg or a diastolic blood pressure greater than or equal to 90 mm Hg.

    High blood pressure can increase the risk of serious health conditions such as heart disease, stroke, kidney disease, and vision loss. If left uncontrolled, it can lead to severe health problems and even death. 

    Therefore, monitoring blood pressure readings regularly and taking appropriate measures to control high blood pressure, including medication, dietary changes, and lifestyle modifications, is crucial.

    Abnormal blood pressure 

    Anomalies in readings can indicate potential health risks, and it’s essential to understand the different categories of blood pressure measurements to ensure proper diagnosis and treatment. 

    The ideal blood pressure is considered normal, with increased blood pressure categorized as elevated, stage 1, or stage 2, depending on the specific numbers. To get an accurate blood pressure measurement, healthcare providers typically consider the average of two or more readings from three or more office visits

    Elevated blood pressure

    .Elevated blood pressure is defined as a systolic number (top) between 120 and 129, with a diastolic number (bottom) below 80. Stage 1 hypertension is a systolic number ranging from 130 to 139 mm Hg or a diastolic between 80 and 89 mm Hg. 

    Stage 2 hypertension is a systolic number of 140 mm Hg or higher or a diastolic of 90 mm Hg or higher. Blood pressure readings above 180/120 mm Hg are considered a hypertensive emergency or crisis and require immediate medical attention.

    High blood pressure, if left untreated, can lead to various health risks, such as heart disease, stroke, kidney damage, vision loss, and cognitive impairment. 

    Therefore, it’s essential to monitor blood pressure levels regularly and seek medical attention if there are any abnormalities in blood pressure readings.

    Blood pressure readings can be affected by various factors

    Blood pressure readings can be affected by various factors, including lifestyle, genetics, and medications. According to the National Heart, Lung, and Blood Institute, some risk factors for high blood pressure, such as unhealthy lifestyle habits, can be changed. 

    Unhealthy lifestyle habits include a poor diet, lack of physical activity, and smoking. On the other hand, some risk factors like age, family history and genetics, race and ethnicity, and sex cannot be changed.

    Dietary changes

    Dietary changes can have a significant impact on blood pressure readings. A study published in Cardiology Clinics suggests that reducing sodium intake, increasing potassium intake, and following a Dietary Approach to Stop Hypertension-style or vegetarian dietary patterns can effectively lower blood pressure.

    Genetics can also play a role in blood pressure readings. 

    The National Institutes of Health reports that genetic factors can contribute to hypertension. For example, certain gene variations can affect the body’s ability to regulate salt and fluid balance, leading to high blood pressure.

    Certain medications 

    Certain medications can also affect blood pressure readings. For example, some medications used to treat high blood pressure, such as diuretics, ACE inhibitors, and beta-blockers, can lower blood pressure. However, other medications like NSAIDs, decongestants, and antidepressants can raise blood pressure.

    Regular monitoring of blood pressure

    Regular monitoring of blood pressure is crucial in managing and preventing the development of hypertension and its complications. It is recommended that adults should have their blood pressure checked at least once a year, but more frequent monitoring may be necessary for those with pre-existing medical conditions or risk factors for high blood pressure.

    To obtain accurate blood pressure readings, certain best practices should be followed. It is important to be seated comfortably with both feet on the floor and the arm supported at heart level. 

    Caffeine and tobacco

    Caffeine and tobacco use should be avoided for at least 30 minutes before the measurement. The cuff size should be appropriate for the arm’s size, and the device used should be calibrated and validated for accuracy.

    Regular blood pressure monitoring

    Regular blood pressure monitoring is especially important for those with hypertension or who is at risk of developing it, as it can help detect changes in blood pressure and facilitate early intervention. 

    By making lifestyle changes, such as increasing physical activity, reducing sodium and alcohol intake, and losing weight, individuals can effectively manage their blood pressure and reduce their risk of developing hypertension and its associated complications.

    In summary

    Regular blood pressure checks are important in managing hypertension and preventing its complications. The frequency of blood pressure checks depends on an individual’s medical history and risk factors. 

    Best practices for obtaining accurate blood pressure readings include proper positioning, avoiding certain substances before the measurement, and using validated and calibrated equipment. 

    Making lifestyle changes can help manage blood pressure and reduce the risk of developing hypertension.