Good blood pressure is a reading 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 climbs above those thresholds, your cardiovascular risk starts to increase, even if you feel perfectly fine.
The Four Blood Pressure Categories
The American Heart Association and American College of Cardiology divide adult blood pressure into four categories, confirmed in their updated 2025 guidelines. If your top and bottom numbers fall into two different categories, the higher category is the one that applies to you.
- 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. It means your heart is working harder than ideal, but you haven’t crossed into hypertension yet. At this stage, lifestyle changes like exercise, reducing sodium, and managing stress can often bring numbers back down. Stage 1 and stage 2 hypertension typically call for more aggressive intervention, and your doctor may recommend medication depending on your overall cardiovascular risk.
What the Top and Bottom Numbers Mean
The top number, systolic pressure, measures the force your blood exerts on artery walls when your heart beats. The bottom number, diastolic pressure, measures that force between beats, when your heart is resting. Both matter, but research shows systolic pressure is the stronger predictor of future heart attacks, strokes, and cardiovascular death regardless of age.
For people under 50, diastolic pressure carries extra weight. A study highlighted by the American Heart Association found that in younger adults, the bottom number provided additional information about cardiovascular risk beyond what the top number alone could predict. So if you’re younger and your doctor flags a diastolic reading of 85, that’s worth paying attention to even if your systolic number looks fine.
When Blood Pressure Is Too Low
A reading below 90/60 mm Hg is considered low blood pressure, or hypotension. For many people, naturally low blood pressure causes no problems at all. It only becomes a concern when it causes symptoms: dizziness, lightheadedness, fainting, or feeling like you might pass out when standing up.
One specific type, orthostatic hypotension, happens when your blood pressure drops significantly after you stand up from sitting or lying down and stays low for more than three minutes. A drop of 20 points or more in the top number, or 10 points or more in the bottom number, meets the threshold. If this happens regularly and you feel unsteady, it’s worth mentioning to your doctor because it raises your risk of falls.
Target Numbers for Diabetes and Kidney Disease
If you have diabetes or chronic kidney disease, the target is tighter than for the general population. Current guidelines recommend keeping blood pressure below 130/80 mm Hg, and some international guidelines push the systolic target even lower, to under 120. Research in the Journal of the American Heart Association found that people with both diabetes and chronic kidney disease had a reduced risk of cardiovascular events when they maintained systolic pressure below 130 and diastolic below 80. The stricter target exists because high blood pressure accelerates kidney damage and compounds the cardiovascular risks that diabetes already carries.
When Numbers Become Dangerous
A reading of 180/120 mm Hg or higher is a hypertensive crisis. At this level, blood vessels can sustain damage within minutes. Symptoms include severe headache, chest pain, blurred vision, shortness of breath, confusion, nausea, and in extreme cases, seizures or unresponsiveness. If your reading hits 180/120 and you’re experiencing any of these symptoms, call 911. If you get a reading that high but feel fine, wait five minutes, recheck, and contact your doctor immediately if it remains elevated.
How to Get an Accurate Reading
Blood pressure fluctuates throughout the day, and a single reading can be misleading. How you prepare and position yourself during measurement makes a real difference in accuracy.
Avoid caffeine, smoking, and exercise for at least 30 minutes before measuring. Empty your bladder, then sit quietly for five minutes without talking or using your phone. When you’re ready, sit with your feet flat on the floor and your arm supported on a flat surface at heart level. Place the cuff on bare skin, not over clothing, with the bottom edge directly above the bend of your elbow. A cuff placed too high, too low, or over a sleeve can skew results by 10 points or more in either direction.
For the most reliable picture, measure at the same time each day. Morning readings before medication and evening readings before bed tend to give your doctor the most useful data. Taking two readings one minute apart and averaging them is a common recommendation for home monitoring.
Blood Pressure in Children
The adult categories above don’t apply to children and teenagers. In kids, normal blood pressure depends on age, sex, and height. A 10-year-old boy at average height, for example, has a typical systolic pressure around 102 and diastolic around 61, well below what would be normal for an adult. Pediatricians use percentile-based charts rather than fixed cutoffs, so there’s no single “good” number for kids. If you’re concerned about your child’s blood pressure, their doctor can compare readings against the appropriate chart for their age and size.