Understand what systolic and diastolic blood pressure numbers mean, how to measure accurately, and what ranges indicate.
Step-by-Step Guide
Know the Two Numbers
A blood pressure reading shows two numbers, e.g. 120/80 mmHg. The top number (systolic) is the pressure when your heart beats. The bottom number (diastolic) is the pressure between beats.
Prepare Correctly Before Measuring
Sit quietly for at least 5 minutes before taking a reading. Avoid caffeine, exercise, and smoking for 30 minutes beforehand. Sit with your back supported, feet flat on the floor, and your arm at heart level.
Place the Cuff Correctly
Wrap the cuff snugly around your bare upper arm, one finger-width above the elbow crease. The tube should run down the inside of your arm. A poorly positioned cuff can give inaccurate readings.
Take Multiple Readings
Take two or three readings one minute apart and use the average. Blood pressure naturally varies throughout the day, so a single measurement may not be representative.
Understand the Categories
Normal: below 120/80 | Elevated: 120–129 / below 80 | High Stage 1: 130–139 / 80–89 | High Stage 2: 140+ / 90+ | Crisis: 180+ / 120+ (seek immediate care). These are American Heart Association guidelines.
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Frequently Asked Questions
Q: Which arm should I use?
A: Use the arm your doctor recommends, or measure both arms on your first check. If there is a consistent difference, always use the arm with the higher reading.
Q: What causes a high reading at the doctor's office?
A: This is called "white coat hypertension" — anxiety raises blood pressure temporarily. Home readings are often more accurate. Use a validated home monitor and keep a log.
Q: How often should I check my blood pressure?
A: If your levels are normal and you have no risk factors, once a year at check-ups is sufficient. If you have high blood pressure or are on medication, your doctor may recommend daily monitoring.