Normal blood pressure is below 120/80 mmHg. That means the top number (systolic) stays under 120 and the bottom number (diastolic) stays under 80. These thresholds were reaffirmed in the 2025 guidelines issued jointly by the American Heart Association and American College of Cardiology, and they apply to all adults regardless of age.
What the Two Numbers Mean
A blood pressure reading gives you two numbers separated by a slash. The top number, systolic pressure, measures the force your blood exerts against artery walls when your heart pumps. The bottom number, diastolic pressure, measures that same force between beats, when your heart is resting and refilling with blood.
Both numbers matter. If your systolic and diastolic readings fall into different categories, you’re classified by whichever category is higher. 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 normal.
Blood Pressure Categories
The current classification system breaks 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
Elevated blood pressure is a warning zone. Your numbers aren’t high enough to qualify as hypertension, but without changes they tend to climb over time. Stage 1 and stage 2 hypertension carry progressively greater risk of heart attack, stroke, and kidney damage. Starting at just 115/75, cardiovascular disease risk doubles with every additional 20 points systolic or 10 points diastolic across the entire range. That doubling effect means the difference between 115/75 and 155/95 represents roughly a fourfold increase in risk.
When Blood Pressure Is Too Low
A reading below 90/60 is generally considered low blood pressure, or hypotension. But low numbers only become a problem if they cause symptoms like dizziness, blurred vision, fatigue, fainting, or trouble concentrating. Some people naturally run on the lower side and feel perfectly fine.
Sudden drops are the real concern. A fall of just 20 points in systolic pressure, say from 110 to 90, can make you feel lightheaded or faint. Extreme drops can lead to shock, which shows up as confusion, cold and clammy skin, rapid shallow breathing, and a weak pulse.
When Blood Pressure Is Dangerously High
A reading of 180/120 or higher is a hypertensive crisis. This can happen without warning even in people who don’t know they have high blood pressure. If your numbers reach this level but you have no other symptoms, it’s classified as severe hypertension. If you also experience chest pain, severe headache, vision changes, confusion, difficulty speaking, sudden weakness in your arms or legs, or seizures, that signals a hypertensive emergency with potential organ damage requiring immediate care.
How to Get an Accurate Reading
Your blood pressure fluctuates throughout the day based on activity, stress, hydration, and even posture. A single reading can be misleading. To get a number you can actually trust, the CDC recommends a specific routine: avoid food and drinks for 30 minutes beforehand, empty your bladder, then sit in a comfortable chair with your back supported for at least five minutes before measuring. Both feet should be flat on the floor with your legs uncrossed. Rest the arm wearing the cuff on a table at chest height, and place the cuff against bare skin rather than over clothing. Don’t talk during the measurement.
Small deviations from this routine can inflate your reading by 5 to 15 points, enough to push a normal result into the elevated or stage 1 range. If you’re monitoring at home, take two or three readings a minute apart and average them. Consistency in technique matters more than any single number.
White Coat and Masked Hypertension
Some people consistently read higher at a doctor’s office than at home. This is called white coat hypertension, and it’s driven by the stress of a medical visit. The reverse also happens: masked hypertension means your numbers look fine in the clinic but run high in everyday life. Both patterns are common enough that doctors may recommend home monitoring or a 24-hour ambulatory monitor to get a clearer picture of your actual blood pressure.
Blood Pressure in Children
There is no single “normal” number for children. Pediatric blood pressure is evaluated using percentile charts that account for a child’s age, sex, and height. A reading at or above the 95th percentile for those factors is considered hypertension. Because kids are growing and their cardiovascular systems are developing, their normal ranges shift year to year. Your child’s doctor tracks these percentiles over time rather than comparing to a fixed adult cutoff.
Why the Same Thresholds Apply at Every Adult Age
Blood pressure does tend to rise with age. Arteries gradually stiffen, and systolic pressure in particular creeps upward over the decades. Older guidelines once set higher acceptable thresholds for older adults, but current evidence shows that keeping blood pressure below 130/80 reduces heart attack and stroke risk even in people over 65. The 2025 guidelines maintain the same category cutoffs for all adults. A reading of 140/90 is stage 2 hypertension whether you’re 35 or 75.