A normal blood pressure reading is below 120/80 mm Hg. That means the top number (systolic) stays under 120 and the bottom number (diastolic) stays under 80. Once either number climbs above those thresholds, your cardiovascular risk starts to increase, even if you feel perfectly fine.
What the Two Numbers Mean
Blood pressure is recorded as two numbers separated by a slash. The top number, systolic pressure, measures the force in your arteries each time your heart beats and pushes blood out. The bottom number, diastolic pressure, measures the force between beats, when your heart is refilling. Both numbers matter, and either one being too high is enough to put you in a higher risk category.
Blood Pressure Categories for Adults
The 2025 guidelines from the American Heart Association and American College of Cardiology break blood pressure into four categories:
- Normal: Below 120/80 mm Hg. No treatment needed, just healthy habits to stay here.
- Elevated: 120 to 129 systolic with diastolic still under 80. This is a warning zone. Without changes, it tends to progress.
- Stage 1 hypertension: 130 to 139 systolic or 80 to 89 diastolic. Lifestyle changes are the first step, and medication may be recommended depending on your overall heart disease risk.
- Stage 2 hypertension: 140 or higher systolic, or 90 or higher diastolic. This typically calls for both lifestyle changes and medication.
If your systolic and diastolic numbers fall into two different categories, you’re classified by whichever category is higher. So a reading of 138/72 counts as Stage 1 hypertension because of the systolic number, even though the diastolic is normal.
Targets Change as You Get Older
For adults aged 18 to 64, the treatment goal is a systolic pressure of 120 to 129 and a diastolic of 70 to 79. But as you age, guidelines get more flexible. Blood vessels stiffen naturally over time, and pushing pressure too low in older adults can cause dizziness, falls, and fainting.
For adults 65 to 79, the primary goal is getting below 140/80. If that’s well tolerated, aiming for 120 to 129 systolic can be considered. For people 80 and older, the target loosens further to a systolic of 140 to 150, with 130 to 139 as a secondary goal if it doesn’t cause problems. After age 85, or for anyone with significant frailty, targets are individualized and typically more lenient, often simply keeping systolic below 140.
These aren’t hard cutoffs. A healthy, active 70-year-old may do well with the same target as a 50-year-old, while someone the same age who’s frail or dealing with a life-limiting illness may benefit from a gentler approach.
Targets for Diabetes and Kidney Disease
If you have diabetes, chronic kidney disease, or both, the target is generally tighter than for the average adult. Current guidelines recommend keeping blood pressure below 130/80 in these cases. A large study of adults with both conditions found that hitting that target was associated with a meaningful reduction in cardiovascular events. The reason for the stricter goal is that high blood pressure accelerates kidney damage and compounds the vascular harm that diabetes already causes.
How to Get an Accurate Reading
A single reading taken under poor conditions can easily be off by 10 to 15 points. To get numbers you can trust, the CDC recommends a specific routine: don’t eat, drink, smoke, consume caffeine, or exercise for 30 minutes before measuring. Empty your bladder. Sit in a chair with your back supported and both feet flat on the floor, legs uncrossed, for at least five minutes before taking the reading. Rest the arm with the cuff on a table at chest height, with the cuff snug against bare skin. Don’t talk while the measurement is happening.
These details aren’t trivial. A full bladder alone can add 10 to 15 points to a systolic reading. Crossed legs can raise it by several points. Talking during measurement, resting the arm in your lap instead of at chest height, or sitting on an exam table with your feet dangling can all skew results upward. If your readings at home consistently differ from those at a clinic, check your technique first.
When Your Reading Depends on Where You Are
Some people have high readings at the doctor’s office but normal readings at home. This is called white coat hypertension, and it’s defined as office blood pressure of 130/80 or above but consistently normal readings (below 130/80) outside the clinic. On its own, without other risk factors, it’s generally considered low risk. The main concern is avoiding unnecessary medication based on inflated office readings.
The opposite pattern is more dangerous. Masked hypertension means your blood pressure reads normal at the clinic but runs high the rest of the time. This is associated with organ damage and cardiovascular risk nearly as high as sustained hypertension, and it’s easy to miss because the office numbers look fine. If you have risk factors for heart disease but consistently normal clinic readings, home monitoring or a 24-hour ambulatory monitor can catch what office visits miss.
How Much Lifestyle Changes Can Move the Numbers
If your blood pressure is in the elevated or Stage 1 range, lifestyle changes alone can sometimes bring it back to normal. The two best-studied strategies are reducing sodium intake and following the DASH diet (rich in fruits, vegetables, whole grains, and low-fat dairy while limiting saturated fat and sweets).
Cutting sodium from a high intake to a low intake lowers systolic pressure by about 6 to 7 points over four weeks. The DASH diet on its own drops systolic pressure by roughly 4 points within the first week, and that effect holds steady for months. Combining both, reducing sodium while eating a DASH-style diet, produces even larger reductions. The diastolic drops are smaller but still meaningful: about 3 points from sodium reduction and 1 point from the DASH diet.
Those numbers might sound modest, but a sustained drop of 5 systolic points is enough to reduce stroke risk by about 13% and heart disease risk by about 10% at a population level. Regular aerobic exercise, maintaining a healthy weight, limiting alcohol, and managing stress each contribute additional reductions that stack with dietary changes.
When Blood Pressure Becomes an Emergency
A reading of 180/120 or higher is considered a hypertensive crisis. If that reading comes with symptoms like chest pain, shortness of breath, severe headache, blurred vision, confusion, nausea, or signs of stroke (sudden numbness or weakness on one side of the body), it’s a medical emergency requiring a call to 911. If the number is that high but you feel fine, wait five minutes, recheck, and contact your doctor promptly if it stays elevated.