Systolic blood pressure (SBP) is the top number in a blood pressure reading, representing the pressure inside your arteries when your heart beats and pumps blood throughout your body. Expressed in millimeters of mercury (mmHg), it reflects the force exerted on artery walls during the heart’s contraction phase, known as systole. SBP is an important indicator of cardiovascular health.
Understanding Your Systolic Blood Pressure Number
The systolic number indicates the maximum pressure within your arteries as blood is ejected from the heart. Medical guidelines, such as those from the American Heart Association (AHA) and American College of Cardiology (ACC), categorize SBP readings to assess cardiovascular risk. A normal SBP is less than 120 mmHg.
Elevated SBP falls between 120 and 129 mmHg, with the diastolic pressure remaining below 80 mmHg. This range suggests an increased risk of developing high blood pressure in the future. Stage 1 hypertension is diagnosed when SBP is between 130 and 139 mmHg, or if the diastolic pressure is between 80 and 89 mmHg.
Stage 2 hypertension is indicated by an SBP of 140 mmHg or higher, or a diastolic pressure of 90 mmHg or higher. Readings exceeding 180 mmHg systolic and/or 120 mmHg diastolic constitute a hypertensive crisis, requiring immediate medical attention.
Measuring Your Systolic Blood Pressure
Measuring SBP accurately requires proper technique, whether at home or in a clinic. Before taking a reading, it is recommended to avoid caffeine, exercise, or smoking for at least 30 minutes. You should also empty your bladder and rest quietly for at least five minutes in a chair with your back supported and feet flat on the floor.
The blood pressure cuff should be placed directly on your bare upper arm, about 2 centimeters above your elbow, ensuring it is at heart level. It is important to use a cuff that fits correctly, as a cuff that is too small can result in an artificially high reading. While taking the measurement, remain still and avoid talking.
Taking two or three readings, each one to two minutes apart, helps ensure accuracy. It is also recommended to measure blood pressure in both arms initially and then consistently use the arm that provides the higher reading. Automated devices are commonly used for home monitoring, with many storing readings and calculating averages over time.
Common Influences on Systolic Blood Pressure
Several factors can temporarily or chronically influence SBP readings. Physical activity causes SBP to rise, with moderate exercise leading to an increase of 20 to 30 mmHg above baseline, while intense exertion can raise it by 40 to 50 mmHg. Emotional states like excitement or anxiety can also elevate blood pressure due to adrenaline release.
Age plays a role, as arterial blood pressure increases with advancing age, and arteries can become stiffer. Until menopause, women have lower arterial pressure than men of the same age, but this equalizes afterward. Sleep lowers blood pressure by 15 to 20 mmHg during deep sleep.
Lifestyle choices, such as diet, can also impact SBP. High sodium intake can increase blood pressure, while conditions like obesity also contribute to higher readings. Certain medical conditions, including kidney disease, thyroid issues, and diabetes, are known to affect SBP. Medications can also influence SBP, with some designed to lower it, while others can temporarily raise it.
Strategies for Healthy Systolic Blood Pressure
Maintaining a healthy SBP involves several actionable lifestyle modifications. Adopting a heart-healthy diet, such as the Dietary Approaches to Stop Hypertension (DASH) diet, which emphasizes whole grains, fruits, vegetables, and low-fat dairy, can significantly lower SBP. Reducing sodium intake to less than 2,300 mg per day is beneficial.
Regular physical activity, including at least 30 minutes of moderate aerobic exercise daily, can lower SBP. Activities like walking, jogging, cycling, or swimming are effective, and strength training at least two days a week also contributes to lower blood pressure. Maintaining a healthy weight is also important, as losing even a small amount of weight can reduce SBP by approximately 1 mmHg for every kilogram lost.
Stress management techniques, such as meditation or deep breathing, can help control temporary SBP spikes caused by stress hormones. Limiting alcohol consumption and avoiding smoking are additional beneficial strategies. Regular medical check-ups are important for monitoring SBP, and a healthcare professional can advise when medication might be necessary.