A good blood pressure reading is below 120/80 mmHg. That threshold, confirmed in the 2025 joint guidelines from the American Heart Association and American College of Cardiology, remains the definition of normal blood pressure for adults. Once either number creeps above that line, your cardiovascular risk starts climbing in a surprisingly predictable way: starting at 115/75 mmHg, your risk of heart disease and stroke doubles with every increase of 20 points in the top number or 10 points in the bottom number.
What the Two Numbers Mean
A blood pressure reading has two numbers, written as one over the other (like 118/76). The top number, called systolic pressure, measures the force your blood exerts against artery walls when your heart beats. The bottom number, diastolic pressure, measures that force between beats, when your heart is resting. Both matter, but systolic pressure becomes the more important predictor of heart disease after age 50, because arteries stiffen and accumulate plaque over time.
Blood Pressure Categories for Adults
The 2025 guidelines use five categories. Only one qualifies as “good.”
- Normal: below 120 systolic and below 80 diastolic
- Elevated: 120 to 129 systolic and below 80 diastolic
- Stage 1 hypertension: 130 to 139 systolic or 80 to 89 diastolic
- Stage 2 hypertension: 140 or higher systolic or 90 or higher diastolic
- Hypertensive crisis: higher than 180 systolic and/or higher than 120 diastolic
Notice the word “or” in the hypertension stages. If either number crosses into a higher category, the higher category applies. So a reading of 118/92 counts as stage 1 hypertension even though the top number looks fine.
Elevated Blood Pressure Is Not Harmless
Readings in the 120 to 129 range (with a bottom number still under 80) fall into the “elevated” category. You won’t get a hypertension diagnosis at this level, but it’s a warning. Without lifestyle changes, elevated blood pressure tends to progress into full hypertension over time. The overarching treatment goal for all adults with high blood pressure is to get below 130/80, which tells you how seriously the guidelines take even modest elevations.
Blood Pressure in Older Adults
After 50, systolic pressure tends to rise as large arteries lose flexibility. Isolated systolic hypertension, where the top number is high but the bottom number stays normal, is the most common form of high blood pressure in older adults. It can cause shortness of breath during light activity, dizziness when standing up too quickly, and falls.
A major 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. That said, aggressive treatment in older adults involves tradeoffs. Lower pressure can cause lightheadedness and increase fall risk, so doctors often weigh overall health and fitness when setting an individual target.
When Blood Pressure Is Too Low
There’s no single cutoff for “too low” the way there is for “too high.” Some people walk around at 90/60 and feel perfectly fine. The concern is symptoms, not a specific number. A sudden drop of just 20 points in systolic pressure, say from 110 to 90, can cause dizziness or fainting. If you consistently feel lightheaded, fatigued, or unsteady, your blood pressure may be lower than your body can handle, even if the number looks reasonable on paper.
Blood Pressure in Children
The under-120/80 target applies to adults. Children and teens have different standards based on age, sex, and height. A typical 10-year-old, for example, has an average blood pressure around 103/61. The threshold for concern at that age starts around 117 to 119 systolic and 76 to 78 diastolic, depending on height. Your child’s pediatrician uses percentile charts to determine whether a reading is normal for their specific age and size.
How to Get an Accurate Reading
A single high reading doesn’t necessarily mean you have high blood pressure. How and when you measure matters enormously. The CDC recommends this process for home monitoring:
- Timing: Don’t eat, drink, or exercise for 30 minutes beforehand. Empty your bladder first.
- Position: Sit in a chair with back support for at least 5 minutes. Keep both feet flat on the floor, legs uncrossed.
- Cuff placement: Rest your arm on a table at chest height. Place the cuff on bare skin, not over clothing.
- During the reading: Don’t talk.
- Repeat: Take at least two readings, 1 to 2 minutes apart, and average them.
Skipping any of these steps can inflate your reading by 5 to 20 points, enough to push a normal reading into the elevated or hypertension range.
White Coat and Masked Hypertension
About 1 in 5 people who get a high reading at the doctor’s office actually have normal blood pressure at home. This phenomenon, called white coat hypertension, reflects the anxiety of a medical visit rather than a true problem. In studies using 24-hour monitoring to verify, the prevalence ranges from 9% to 23% depending on the population.
The opposite pattern is more dangerous: normal readings in the clinic but high blood pressure the rest of the time. This is called masked hypertension, and it affects roughly 10% to 20% of people, with men slightly more likely to have it than women (about 18% versus 11% in Canadian data). Because it flies under the radar at routine checkups, home monitoring is the main way to catch it.
What a Hypertensive Crisis Looks Like
A reading above 180/120 is a hypertensive crisis. At this level, the distinction that matters is whether organs are being damaged. If you see a number this high but have no symptoms, it’s classified as severe hypertension (previously called hypertensive urgency). If you also have chest pain, difficulty breathing, vision changes, numbness, or confusion, that’s a hypertensive emergency requiring immediate medical care. Either way, a reading above 180/120 is not something to monitor and wait on.