Normal blood pressure is below 120/80 mm Hg. That first number (systolic) measures pressure when your heart beats, and the second (diastolic) measures pressure between beats. Readings above or below that normal range fall into distinct categories, each with different implications for your health.
The Five Blood Pressure Categories
The American Heart Association classifies blood pressure into these ranges:
- 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
- Hypertensive Crisis: Systolic above 180 and/or diastolic above 120
Notice that “elevated” blood pressure only involves the top number creeping up. The bottom number stays below 80. This stage is a warning sign that you’re trending toward hypertension, and lifestyle changes at this point can often keep you from progressing.
For Stage 1 and Stage 2, only one of the two numbers needs to be in the high range to qualify. If your systolic is 135 but your diastolic is 75, that’s still Stage 1 hypertension based on the top number alone.
When Blood Pressure Is Too Low
A reading below 90/60 mm Hg is generally considered low blood pressure, or hypotension. Unlike high blood pressure, low blood pressure isn’t defined by rigid stages. It’s only a concern when it causes symptoms: dizziness, blurred vision, fatigue, trouble concentrating, fainting, or nausea. Some people naturally run low without any problems at all.
Severely low blood pressure can lead to shock, which involves confusion (particularly in older adults), cold and clammy skin, rapid shallow breathing, and a weak pulse. This is a medical emergency, but it’s rare outside of major blood loss, severe infection, or allergic reactions.
How European and American Guidelines Differ
If you’ve seen conflicting numbers online, it’s likely because the two major guideline systems don’t fully agree. The 2017 American guidelines lowered the hypertension threshold to 130/80 mm Hg. The 2024 European Society of Cardiology guidelines kept hypertension at the traditional 140/90 mm Hg, classifying anything from 120/70 to 139/89 as “elevated” rather than hypertension.
This doesn’t mean the Europeans ignore 130/80 readings. Both systems recommend medication at 140/90 for nearly all adults. The difference is in the 130 to 139 range: American guidelines call it Stage 1 hypertension and recommend medication for people with existing heart disease, diabetes, kidney disease, or a 10-year cardiovascular risk of 10% or higher. European guidelines take a similar approach but recommend trying lifestyle changes for three months first in many of those same higher-risk groups before adding medication. For lower-risk people in that 130 to 139 range, both systems emphasize diet, exercise, and monitoring.
Blood Pressure Ranges in Children
The adult categories above don’t apply to children. In kids, normal blood pressure depends on age, sex, and height. A reading that’s perfectly fine for a 14-year-old could be high for a 6-year-old. Pediatric blood pressure is evaluated using percentile charts from the National Heart, Lung, and Blood Institute, which map out expected ranges for boys and girls from ages 1 through 17 at different heights. Readings above the 95th percentile for a child’s age and height group are considered hypertensive. Your child’s pediatrician uses these charts at routine checkups, so there’s no single number to memorize.
Do Ranges Change as You Age?
Older guidelines used a higher threshold for people over 65, setting “normal” at up to 150/80 instead of 140/90. Current American guidelines dropped that distinction. The same categories now apply regardless of age, largely because the major clinical trial that informed the 2017 guidelines (the SPRINT trial) evaluated patients across age groups without finding a reason to set a separate, more lenient target for older adults.
That said, blood pressure does tend to rise with age as arteries stiffen. A systolic reading in the 130s is far more common at 70 than at 30. Doctors weigh the benefits of aggressive treatment against the risk of side effects like dizziness or falls in older patients, so the target your doctor sets for you may differ from the textbook categories.
Why Your Reading Might Be Wrong
Before worrying about where you fall, it’s worth knowing that blood pressure readings are surprisingly easy to get wrong. A cuff that’s too small for your arm can inflate your systolic reading by up to 20 mm Hg. In a study of 165 adults, people who needed a large or extra-large cuff but were measured with a standard one got readings nearly 20 points too high. That’s enough to push a perfectly normal reading into Stage 1 hypertension territory.
Cuff size isn’t the only factor. Sitting on an exam table with your back unsupported (instead of a chair with back support) can add 5 to 15 points to the top number. Crossing your legs or letting them dangle adds another 5 to 8 points. A cuff that’s too large, on the other hand, only lowers the reading by 1 to 6 points.
For the most accurate reading at home or in a clinic, sit in a chair with your back supported and feet flat on the floor. Rest your arm on a table so the cuff is at heart level. Don’t talk during the measurement. And make sure the cuff fits: the inflatable bladder should wrap around at least 80% of your upper arm. If you’ve been getting borderline readings, an ill-fitting cuff or poor positioning could be the entire explanation.
What Each Category Means in Practice
A single high reading doesn’t mean you have hypertension. Blood pressure fluctuates throughout the day based on stress, caffeine, activity, and even the temperature. Diagnosis typically requires elevated readings on at least two separate occasions.
If your numbers are in the elevated range (120 to 129 systolic), the focus is entirely on lifestyle: reducing sodium, increasing physical activity, managing stress, and limiting alcohol. No medication is recommended at this stage.
Stage 1 hypertension (130 to 139 systolic or 80 to 89 diastolic) adds a layer of risk assessment. If your overall cardiovascular risk is low, lifestyle changes alone may be enough. If you have other risk factors like diabetes or a family history of heart disease, medication enters the conversation.
Stage 2 hypertension (140+ systolic or 90+ diastolic) almost always involves both lifestyle changes and medication, regardless of other risk factors.
A hypertensive crisis, with readings above 180/120, requires immediate attention. If you see that number and have symptoms like chest pain, shortness of breath, vision changes, or severe headache, call emergency services. If the reading is that high but you feel fine, wait five minutes, retake it, and contact your doctor if it stays elevated. The distinction matters: very high readings without organ damage (sometimes called severe hypertension) are managed urgently but less aggressively than a true hypertensive emergency where organs are being harmed.