What Is Systolic Blood Pressure?
Systolic blood pressure — the top number in a reading — measures the force in your arteries at the exact moment your heart contracts and pushes blood out. It's the number most guidelines lean on most heavily when tracking cardiovascular risk over time.
What to know about systolic pressure
What it measures
The peak pressure against your artery walls during a heartbeat — the moment your heart is working hardest.
What's considered normal
Under the AHA guideline, under 120 mmHg is Normal, 120–129 is Elevated, and 130 or above starts crossing into High ranges.
Why it tends to rise with age
Arteries stiffen gradually over time, which raises the pressure needed to push blood through them — a major reason systolic often climbs faster than diastolic later in life.
What can spike it short-term
Caffeine, stress, physical activity, a full bladder, and "white coat" anxiety at the doctor's office can all temporarily raise a single systolic reading.
What Is Systolic Blood Pressure? — FAQ
What is a dangerously high systolic reading?
A systolic reading above 180 mmHg is considered a hypertensive crisis and needs immediate medical attention, particularly if paired with symptoms like chest pain or shortness of breath.
Can CardiLog show how my systolic number trends over time?
Yes. CardiLog's Insights screen charts your systolic (and diastolic) trend over 7, 30, and 90 days, with a normal range band for context.
Start tracking today.
Your doctor checks your BP twice a year. CardiLog watches it every day.
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