A good blood pressure reading is below 120/80 mmHg. That first number (systolic) measures pressure when your heart beats, and the second number (diastolic) measures pressure between beats. Both numbers matter, and if they fall into different categories, the higher category is the one that applies to you.
Blood Pressure Categories for Adults
The 2025 guidelines from the American Heart Association and American College of Cardiology break blood pressure into four levels:
- 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 puts you in one category and your diastolic puts you in another, your reading is classified by whichever number is higher. So a reading of 135/78 counts as stage 1 hypertension because of the systolic number, even though the diastolic looks fine.
Why Below 120 Matters
A major clinical trial called SPRINT tested whether pushing systolic pressure below 120 produced better outcomes than the older target of below 140. In adults 50 and older with at least one additional heart disease risk factor, the lower target reduced cardiovascular events like heart attack, heart failure, and stroke by 25%. It also lowered the overall risk of death by 27%. These results are a big part of why current guidelines set “normal” at below 120 rather than treating anything under 140 as acceptable.
Targets for Older Adults
For years, some physicians believed systolic pressure could safely run as high as 150 in people over 65. That thinking has shifted. Current guidelines recommend that most older adults aim for the same target as everyone else: below 130/80. The SPRINT data included older participants and showed clear benefits from tighter control. That said, individual targets can vary depending on other health conditions, medication side effects, and fall risk, so the specific goal for any person over 65 is something to work out with a doctor.
Blood Pressure During Pregnancy
Pregnancy uses different thresholds. High blood pressure during pregnancy is defined as a reading of 140/90 or higher on two occasions at least four hours apart. Severe high blood pressure during pregnancy is 160/110 or higher on two or more readings. These numbers are taken seriously because elevated pressure during pregnancy raises the risk of complications like preeclampsia. If you’re pregnant and tracking your numbers at home, those are the cutoffs to know.
When Numbers Are Too Low
Blood pressure below 90/60 is generally considered low. But low blood pressure only becomes a medical concern when it causes symptoms like dizziness, fainting, or blurred vision. A drop of just 20 points in systolic pressure, say from 110 to 90, can be enough to make you feel lightheaded. Some people naturally run on the lower end and feel perfectly fine. The number alone doesn’t tell the whole story.
When Numbers Are Dangerously High
A reading of 180/120 or higher is classified as a hypertensive crisis. There are two types. If you hit those numbers but feel fine, it’s considered severe hypertension (previously called hypertensive urgency). If you have symptoms like chest pain, headache, shortness of breath, or vision changes at that level, it may be a hypertensive emergency, meaning organs like the heart, brain, or kidneys could be sustaining damage.
If your reading is 180/120 or higher and you have symptoms, call 911. If you don’t have symptoms, rest for a few minutes and recheck. If it stays that high, seek medical care promptly.
Your Readings May Vary by Setting
Roughly 1 in 5 people diagnosed with high blood pressure in a clinic actually have normal pressure at home. This is called white-coat hypertension, and studies consistently find it affects about 20 to 25% of people with elevated clinic readings. The reverse also happens: about 12 to 13% of adults have normal readings in the office but elevated pressure the rest of the time (masked hypertension). In the U.S., that translates to an estimated 17 million adults walking around with undetected high blood pressure.
This is why home monitoring matters. A single reading in a doctor’s office is a snapshot, not the full picture. If your numbers seem borderline or inconsistent, tracking them at home over days or weeks gives a much more reliable average.
How to Get an Accurate Reading
The way you sit, breathe, and position your arm all affect your numbers. To get a reading that actually reflects your blood pressure:
- Sit with your back supported for at least 5 minutes before taking the measurement.
- Keep both feet flat on the floor with your legs uncrossed. Crossing your legs can artificially raise your reading.
- Rest your arm on a table at chest height. Letting your arm hang at your side pushes the numbers up.
- Avoid food, drinks, and caffeine for 30 minutes beforehand.
- Empty your bladder first. A full bladder can raise systolic pressure.
- Don’t talk during the reading.
Small details make a real difference. Simply crossing your legs or dangling your arm can add several points to your reading, enough to push you from one category into the next.
How Diet and Sodium Affect Your Numbers
If your blood pressure is in the elevated or stage 1 range, dietary changes can bring it down meaningfully. The DASH diet (heavy on fruits, vegetables, whole grains, and lean protein, light on saturated fat and red meat) combined with cutting sodium to about 1,500 mg per day, roughly half a teaspoon of salt, lowered blood pressure more than either change alone. In clinical trials, blood pressure dropped with each step down in sodium intake, and participants who followed the full DASH approach plus sodium reduction saw the biggest improvements. For people in the borderline range, these changes can sometimes be enough to move the numbers back into normal territory without medication.