Normal blood pressure for adults is below 120/80 mm Hg. That means a systolic reading (the top number) under 120 and a diastolic reading (the bottom number) under 80. Once either number crosses those thresholds, your blood pressure falls into a higher category, even if the other number stays in the normal range.
Blood Pressure Categories for Adults
The 2025 guidelines from the American Heart Association and American College of Cardiology break adult blood pressure into four categories:
- Normal: Systolic below 120 and diastolic below 80
- Elevated: Systolic 120 to 129 and diastolic below 80
- Stage 1 hypertension: Systolic 130 to 139 or diastolic 80 to 89
- Stage 2 hypertension: Systolic 140 or higher, or diastolic 90 or higher
One important rule: if your two numbers fall into different categories, you’re classified by the higher one. So a reading of 135/75 counts as stage 1 hypertension because of the systolic number, even though the diastolic is technically normal.
These thresholds apply to all adults regardless of age. Before 2017, older adults had a more relaxed target of 150/80, but that distinction was dropped after a major clinical trial showed that tighter control benefited patients across all age groups.
What the Two Numbers Mean
The top number, systolic pressure, measures the force against your artery walls when your heart beats. The bottom number, diastolic pressure, measures that force between beats, when your heart is relaxing and refilling with blood. Both matter, but systolic pressure tends to rise with age and is the stronger predictor of heart disease in people over 50.
A reading like 115/75 is perfectly healthy. So is 105/68. There’s no single “ideal” number within the normal range. Blood pressure that’s consistently very low (below about 90/60) can cause dizziness and fainting, but that’s a separate condition, not the low end of the normal range for most people.
Your Blood Pressure Changes Throughout the Day
Blood pressure isn’t static. It follows a natural 24-hour rhythm, dropping 10% to 15% during sleep compared to waking hours. It typically hits its lowest point in the middle of the night and rises in the early morning hours before you wake up. This overnight dip is actually a sign of healthy cardiovascular function. People whose blood pressure doesn’t drop at night, a pattern called “non-dipping,” face a higher risk of heart and kidney problems.
Beyond the sleep cycle, your readings will fluctuate based on stress, caffeine, physical activity, a full bladder, even conversation. A single high reading doesn’t mean you have hypertension. Diagnosis requires elevated readings across multiple visits or through home monitoring over time.
How to Get an Accurate Reading
The circumstances around a reading matter almost as much as the number itself. The CDC recommends sitting in a comfortable chair with your back supported for at least five minutes before measuring. Both feet should be flat on the ground, legs uncrossed. Rest the arm with the cuff on a table at chest height, and make sure the cuff sits against bare skin, not over clothing.
Skipping these steps inflates your numbers. Crossing your legs can add several points to your reading. Talking during the measurement does the same. A cuff that’s too small for your arm will also give a falsely high result. If you’ve ever been told your blood pressure is borderline, it’s worth asking whether the reading conditions were ideal before worrying.
White Coat and Masked Hypertension
Between 15% and 30% of people with elevated readings in a doctor’s office actually have normal blood pressure outside of it. This is white coat hypertension, named because the stress of a medical visit temporarily raises the numbers. It’s diagnosed when your office reading is high but a 24-hour ambulatory monitor or consistent home readings show normal values.
The opposite problem, masked hypertension, is more dangerous. This is when your blood pressure looks fine in the office but runs high at home, during sleep, or during daily activities. Because it goes undetected in routine checkups, it often causes organ damage silently. Home monitoring is the simplest way to catch it.
Blood Pressure During Pregnancy
The normal range during pregnancy is the same as for other adults: below 120/80. But the thresholds for diagnosing high blood pressure in pregnancy are slightly different from the general hypertension categories. A reading of 140/90 or higher on two occasions at least four hours apart is considered high. Severe hypertension in pregnancy starts at 160/110.
Gestational hypertension refers to high blood pressure that develops for the first time after 20 weeks of pregnancy in someone who previously had normal readings. When that high blood pressure is accompanied by protein in the urine or other organ problems, it’s called preeclampsia. Both conditions require close monitoring because they can escalate quickly.
How Children’s Blood Pressure Is Measured Differently
There is no single “normal” number for children. Instead, a child’s blood pressure is compared to other children of the same age, sex, and height using percentile charts developed by the National Institutes of Health. A reading below the 90th percentile for their demographic group is considered normal. Between the 90th and 95th percentile is elevated, and above the 95th is hypertension.
This means a blood pressure of 110/70 might be perfectly normal for a tall 14-year-old but elevated for a small 8-year-old. Pediatric readings only start to follow adult categories once a child turns 13.
When Blood Pressure Becomes Dangerous
A reading of 180/120 or higher is a hypertensive crisis. If that number appears alongside symptoms like severe headache, chest pain, blurred vision, confusion, nausea, or seizures, it’s considered a hypertensive emergency with active organ damage. Without those symptoms, it’s classified as hypertensive urgency, which is still serious but less immediately life-threatening.
Most people with high blood pressure feel nothing at all, which is why it’s called a silent condition. Readings in the 140s or 150s rarely produce noticeable symptoms. The damage happens gradually, to blood vessels, kidneys, the heart, and the brain, over years of sustained pressure. Regular monitoring is the only way to catch it before that damage accumulates.