Normal blood pressure is anything 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 crosses those thresholds, your blood pressure falls into a higher category, from “elevated” all the way up to stage 2 hypertension.
What the Two Numbers Mean
A blood pressure reading always has two numbers, like 118/76. The top number, systolic pressure, measures the force inside your arteries when your heart contracts and pushes blood out. The bottom number, diastolic pressure, measures the pressure between beats, when the heart is resting. Diastolic is always lower because the arteries aren’t under active pumping force during that pause.
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: 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
If your systolic and diastolic numbers fall into two different categories, you’re classified in the higher one. So a reading of 135/72 counts as stage 1 hypertension because of the systolic number, even though the diastolic looks fine.
European Guidelines Use a Different Cutoff
If you’ve seen conflicting definitions online, that’s because American and European guidelines don’t fully agree. The 2024 European Society of Cardiology guidelines define hypertension as 140/90 mm Hg or higher, while the American guidelines set it at 130/80. Europe also introduced a simpler three-tier system: nonelevated (below 120/70), elevated (120 to 139 systolic or 70 to 89 diastolic), and hypertension (140/90 or above). The practical difference is that someone with a reading of 134/84 would be diagnosed with hypertension in the U.S. but classified as “elevated” in Europe.
Both sets of guidelines agree, however, that the ideal treatment target for most adults is a systolic pressure in the 120 to 129 range. The disagreement is mainly about when to start medication.
When Blood Pressure Is Too Low
While most of the focus goes to high readings, blood pressure can also be too low. A reading below 90/60 mm Hg is considered hypotension. Many people naturally run on the low side without any symptoms, and that’s not a problem. Hypotension only becomes a concern when it causes dizziness, fainting, blurred vision, or fatigue that interferes with your daily life.
There’s also a specific type called orthostatic hypotension, where your pressure drops more than 20 points systolic or 10 points diastolic when you stand up from sitting, and stays low for more than three minutes. A brief dip when changing positions is normal. A prolonged one is not.
Blood Pressure During Pregnancy
Pregnancy uses a separate threshold. High blood pressure in pregnancy is defined as 140/90 or higher on two readings taken at least four hours apart. Severe high blood pressure is 160/110 or higher on two or more occasions. Gestational hypertension refers to high readings that develop during pregnancy in someone who previously had normal blood pressure. When high blood pressure appears after 20 weeks and is accompanied by protein in the urine or other organ problems, it’s classified as preeclampsia.
Blood Pressure in Children
Children don’t share the same fixed cutoffs as adults. Normal pediatric blood pressure depends on the child’s age, sex, and height. Rather than a single number, doctors compare a child’s reading against percentile charts. A reading at or above the 95th percentile for their age and size group is considered high. This means there’s no single “normal” number for kids the way there is for adults.
How to Get an Accurate Reading
Blood pressure is surprisingly easy to measure wrong. A rushed reading, crossed legs, or an arm hanging at your side can all skew the numbers enough to push you into a different category. The CDC recommends the following for an accurate reading:
- Sit with your back supported for at least five minutes before taking a measurement.
- Keep both feet flat on the floor with your legs uncrossed.
- Rest your arm on a table at chest height with the cuff positioned at heart level.
A single reading is also just a snapshot. Blood pressure fluctuates throughout the day based on stress, caffeine, physical activity, and even whether you need to use the bathroom. That’s why a diagnosis of high blood pressure is based on a pattern of elevated readings over time, not one trip to the pharmacy kiosk. If you’re monitoring at home, take readings at the same time each day and track the trend rather than fixating on any individual number.
What Counts as a Hypertensive Crisis
A reading of 180/120 or higher is a hypertensive crisis and requires immediate attention. If that reading is accompanied by chest pain, shortness of breath, severe headache, blurred vision, seizures, or symptoms of stroke, call 911. Even without symptoms, a reading that high warrants urgent contact with a healthcare provider, as organ damage can occur at those levels without obvious warning signs.