A good blood pressure reading is less than 120/80 mmHg. That’s the threshold the American Heart Association defines as normal, and it’s the target associated with the lowest risk of heart disease and stroke. The two numbers represent different phases of your heartbeat: the top number (systolic) measures pressure when your heart pumps blood out, and the bottom number (diastolic) measures pressure when your heart relaxes between beats.
Blood Pressure Categories
Blood pressure falls into distinct categories, and each one carries different implications for your health:
- Normal: Less than 120 systolic and less than 80 diastolic
- Elevated: 120 to 129 systolic with a diastolic still under 80
- Stage 1 hypertension: 130 to 139 systolic or 80 to 89 diastolic
- Stage 2 hypertension: 140 or higher systolic or 90 or higher diastolic
Notice the word “or” in the hypertension stages. If either number is elevated, the higher category applies. You could have a systolic of 125 but a diastolic of 85, and that still qualifies as Stage 1 hypertension.
A reading of 180/120 or higher is a hypertensive crisis. If that number appears alongside chest pain, shortness of breath, blurred vision, severe headache, or signs of stroke (numbness on one side of the body, trouble speaking or walking), it’s a medical emergency.
Why Both Numbers Matter
Your systolic number reflects the peak force your blood exerts against artery walls when the heart contracts. Your diastolic number captures the baseline pressure that remains while the heart rests between beats. Both contribute to cardiovascular risk, but they behave differently as you age.
In older adults, arteries stiffen over time. This often pushes the systolic number above 130 while the diastolic stays below 80, a pattern called isolated systolic hypertension. It’s extremely common after age 65 and is a major reason doctors tend to pay more attention to the top number in older patients. An NIH-funded trial called SPRINT found that lowering systolic pressure to below 120 in adults 50 and older significantly reduced the risk of cardiovascular disease and death.
For every 10 mmHg increase in systolic pressure, the risk of stroke rises by about 14%, based on data from a large American Heart Association study. That incremental risk is why even readings in the “elevated” range deserve attention, not just numbers that cross into full hypertension.
How to Get an Accurate Reading
A single reading in a doctor’s office doesn’t always reflect your true blood pressure. Roughly 1 in 5 people with high readings in a clinic actually have normal pressure at home, a phenomenon called white coat hypertension. The reverse also happens: about 13% of people show normal numbers at the doctor’s office but run high the rest of the time, which is called masked hypertension. Home monitoring catches both patterns.
To get a reliable reading at home, the CDC recommends a specific routine. Don’t eat, drink, or use caffeine for 30 minutes beforehand. Empty your bladder. Sit in a chair with your back supported for at least 5 minutes before measuring. Keep both feet flat on the floor, legs uncrossed, and rest your cuffed arm on a table at chest height. The cuff should sit on bare skin, not over clothing. Don’t talk during the reading.
Small deviations from this routine can skew your numbers by 5 to 15 points. A full bladder alone can add 10 to 15 mmHg to your systolic reading. If your numbers seem surprisingly high or low, check your setup before worrying.
Lowering Blood Pressure Through Diet
The most studied dietary approach is the DASH diet, which emphasizes fruits, vegetables, whole grains, and lean protein while limiting saturated fat and sodium. In clinical trials, people following the DASH diet saw systolic pressure drop by about 4 mmHg within the first week compared to a typical American diet. That reduction held steady through 12 weeks of follow-up.
Cutting sodium amplifies the effect. Reducing sodium intake from high to low on a standard diet lowered systolic pressure by about 7 mmHg after four weeks, with diastolic dropping by roughly 3.4 mmHg. Combining sodium reduction with the DASH diet produces even larger shifts. For someone sitting at 135/85, these changes alone could potentially bring readings back into normal range.
How Exercise Affects Blood Pressure
Regular physical activity lowers systolic pressure by 4 to 10 mmHg and diastolic by 5 to 8 mmHg, according to Mayo Clinic. That’s comparable to what some blood pressure medications achieve. The effect applies to both aerobic exercise (walking, cycling, swimming) and resistance training, though aerobic activity has the larger body of evidence behind it.
The reduction doesn’t require extreme fitness. Consistent moderate activity, roughly 150 minutes per week, produces most of the benefit. The catch is that the effect fades if you stop. Blood pressure tends to creep back up within a few weeks of becoming sedentary again, which makes regularity more important than intensity.
Blood Pressure Targets for Older Adults
The general target of under 120/80 applies to most adults, but for people over 65, the picture gets more nuanced. Aggressive lowering can sometimes cause dizziness, falls, or kidney problems in older adults, especially those taking multiple medications or living with other chronic conditions. Doctors often weigh the benefits of tight blood pressure control against these risks on a case-by-case basis.
That said, the SPRINT trial provided strong evidence that targeting a systolic below 120 in adults 50 and older reduced heart attacks, strokes, and death, even in participants over 75. The question isn’t whether lower is better in general. It is. The question is whether the path to getting there is safe for a particular person given their full health picture.