A blood pressure reading has two numbers, like 128/82. Most people know that lower is usually better, but not what each number means or when a reading is worth a phone call. Here's a plain guide.
What the two numbers mean
The top number is systolic pressure, the force in your arteries when your heart beats. The bottom number is diastolic pressure, the force while your heart rests between beats. Both are measured in millimeters of mercury (mm Hg).
Both numbers matter. After about age 50, the top number tends to be the better predictor of heart and stroke risk, but a high bottom number is still a reason to act.
The ranges
These are the categories used by the American Heart Association:
| Category | Top number | Bottom number | |
|---|---|---|---|
| Normal | below 120 | and | below 80 |
| Elevated | 120 to 129 | and | below 80 |
| High, stage 1 | 130 to 139 | or | 80 to 89 |
| High, stage 2 | 140 or higher | or | 90 or higher |
| Severe | above 180 | and/or | above 120 |
If your two numbers fall in different categories, the higher category is the one that counts. A reading of 126/88 is stage 1, because of the bottom number.
One reading isn't a diagnosis
Blood pressure moves all day. Coffee, a full bladder, a walk from the parking lot, or being nervous in the exam room can all push it up. That's why we look at several readings over time before calling it high blood pressure.
Home readings help a lot. To get a reading you can trust:
- Sit quietly for five minutes first, back supported, feet flat, arm resting at heart level.
- Skip caffeine, exercise and smoking for 30 minutes before.
- Use a cuff that fits your upper arm. A cuff that's too small reads high.
- Take two readings a minute apart, morning and evening, for a week. Write them down or use the cuff's memory.
Bring the cuff to your next visit. We can check it against ours.
When to call
Call 911 if your reading is above 180/120 and you have chest pain, shortness of breath, back pain, numbness or weakness, a change in vision, or trouble speaking.
Call the office the same day if you get a reading above 180/120 with no symptoms. Rest five minutes and measure again first.
Make an appointment if your home readings are regularly 130/80 or higher.
What we can do about it
For many people, the first steps are changes you make at home: less salt, more vegetables and fruit, regular walking, less alcohol, and weight loss if you need it. When medicine is needed, there are several kinds, and finding the right one can take a visit or two.
High blood pressure is one of the most common things our primary care clinicians treat. If it's linked to heart disease, an irregular heartbeat or other heart problems, our cardiologists are in the same practice and see the same chart, so your care stays in one place.
