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 crosses those thresholds, your reading falls into a higher category, from “elevated” all the way up to Stage 2 hypertension.
What the Two Numbers Mean
Blood pressure is always written as two numbers separated by a slash. The first (top) number is your systolic pressure, which measures the force of blood pushing against your artery walls each time your heart beats. The second (bottom) number is your diastolic pressure, the force between beats when your heart is relaxing and refilling with blood.
Both numbers matter. If your systolic and diastolic readings fall into different categories, you’re classified in the higher one. So a reading of 135/75 counts as Stage 1 hypertension because the top number is in that range, even though the bottom number is technically normal.
Blood Pressure Categories for Adults
The 2025 guidelines from the American Heart Association and American College of Cardiology define 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
These categories are based on the average of at least two careful readings taken on at least two separate occasions. A single high reading doesn’t necessarily mean you have hypertension.
What Counts as a Hypertensive Crisis
A reading of 180/120 or higher is considered a hypertensive crisis. At this level, there are two possibilities. If your blood pressure is extremely high but there’s no sign of organ damage, it’s classified as severe hypertension (formerly called hypertensive urgency). You may have no symptoms at all, or you might notice a mild headache, anxiety, a nosebleed, or shortness of breath.
If the same extreme reading comes with signs of organ damage, it’s a hypertensive emergency. Symptoms can include chest pain, severe headache, vision changes, confusion, seizures, or stroke-like symptoms such as facial droop or sudden weakness in your arms or legs. This requires immediate emergency care.
How Blood Pressure Differs in Children
The under-120/80 standard applies to adults. In children and teenagers, normal blood pressure is lower and varies by age, sex, and height. A 1-year-old boy, for instance, typically has a reading around 80/34 to 89/39. By age 10, that average rises to roughly 97/58 to 106/63. A 17-year-old boy’s typical reading is around 114/65 to 122/70, approaching the adult range. Girls follow a similar upward pattern with slightly different numbers at each age.
Pediatric blood pressure is evaluated using percentile charts rather than fixed cutoffs, so a child’s reading is compared against others of the same age, sex, and height.
Blood Pressure Targets for Older Adults
A major NIH-funded trial called SPRINT found that lowering systolic pressure to below 120 in adults age 50 and older significantly reduced the risk of cardiovascular disease and death. That said, treatment targets for older adults often depend on other health conditions and overall fitness. The same aggressive target isn’t always appropriate for someone who is frail or managing multiple chronic conditions.
Why Your Reading Can Vary
Blood pressure fluctuates throughout the day, even within minutes, based on what you’re doing. Physical activity, salty foods, alcohol, lack of sleep, emotional stress, and even your body position all shift the numbers. Sudden stress or anxiety activates your nervous system and temporarily drives blood pressure up. This is normal and doesn’t mean you have hypertension.
There are also two well-known patterns that complicate diagnosis. White-coat hypertension means your readings run high at the doctor’s office but are normal at home. This affects roughly 9% to 24% of people, depending on how it’s defined. Masked hypertension is the opposite: normal readings in the clinic but elevated readings outside of it. Both patterns are common enough that out-of-office monitoring, either at home or with a 24-hour ambulatory cuff, is now recommended to confirm a hypertension diagnosis.
How to Get an Accurate Reading
A blood pressure reading is only useful if it’s taken correctly. Small details make a surprising difference. The CDC recommends following these steps:
- Sit and rest for at least 5 minutes in a comfortable chair with your back supported before taking a reading.
- Position your arm at chest height on a table, with the cuff on bare skin (not over clothing).
- Keep both feet flat on the floor with your legs uncrossed.
- Don’t talk while the measurement is happening.
- Avoid food, drinks, and caffeine for 30 minutes beforehand.
- Empty your bladder before the reading.
- Take at least two readings spaced 1 to 2 minutes apart and use the average.
Skipping even one of these steps, like sitting with crossed legs or talking during the measurement, can inflate your reading by several points and push a normal result into the elevated range. If you’re monitoring at home, using a validated upper-arm cuff (not a wrist monitor) and following the same routine each time gives you the most reliable numbers to share with your doctor.