The four everyday categories

Blood pressure is written as two numbers in millimeters of mercury, abbreviated mm Hg. The top number (systolic) is the pressure when the heart beats. The bottom number (diastolic) is the pressure between beats. A separate article in this series explains what each number describes; here the job is only to sort them. The 2025 guideline defines the categories this way.

1. 1 Normal: top number under 120 and bottom number under 80.
2. 2 Elevated: top number 120 to 129 and bottom number under 80.
3. 3 Stage 1 hypertension: top number 130 to 139 or bottom number 80 to 89.
4. 4 Stage 2 hypertension: top number 140 or higher or bottom number 90 or higher.

Notice the connecting words. Normal and elevated require both numbers to qualify. Stage 1 and stage 2 need only one. That is why 128/84 lands in stage 1: the top number alone would be elevated, but the bottom number of 84 pulls the reading into the stage 1 range. The same logic puts 142/78 in stage 2 because of the top number alone, and 118/92 in stage 2 because of the bottom number alone. Whenever the two numbers point to different categories, the higher category applies.

Elevated is the slot people most often misread. It does not mean mildly high on both numbers. It is a narrow band: systolic 120 to 129 with diastolic still under 80. If the bottom number reaches 80, the reading is no longer elevated; it is at least stage 1.

Hypertension is simply the medical word for high blood pressure. Stage 1 and stage 2 say nothing about how you feel or how long you have had it. They are ranges on a scale that predicts risk. The guideline estimates that the chance of a heart attack, stroke, or other cardiovascular event roughly doubles with each 20 mm Hg rise in systolic pressure or 10 mm Hg rise in diastolic pressure.

Stage 1 is also where an enormous number of adults sit. The guideline estimates that 46.7 percent of US adults, based on national survey data from 2017 to 2020, either had blood pressure of 130/80 or higher or were taking medicine for it. Among people ages 60 to 74 the figure was about 71 percent. Landing in stage 1 puts you in very common company. Whether it calls for medicine depends on your overall risk, which a separate article in this series covers.

Why the average matters more than any one number

Blood pressure moves constantly. It rises when you talk, rush, hold a full bladder, or feel tense in an exam room, and it settles when you sit quietly for five minutes. One number is a snapshot of one moment. That is why the 2025 guideline bases the category on an average of two or more readings on two or more occasions, and why it recommends confirming a suspected diagnosis with out of office readings, at home or with a 24 hour wearable monitor, before treatment begins. Mayo Clinic describes the same standard: a diagnosis is usually based on the average of two or more readings taken on separate occasions.

In practice this means a few things for you.

1. 1 One high reading at a pharmacy kiosk or a clinic visit does not place you in a category. It is a reason to measure again, carefully, over several days.
2. 2 One normal reading does not clear you either. Some people run normal in the office and high at home, a pattern called masked hypertension. The guideline treats it as carrying about the same risk as blood pressure that is high everywhere.
3. 3 The reverse also happens. White coat hypertension means readings are high in the office but not high outside it. It carries less risk, though it can progress over time, so it still warrants follow up.
4. 4 The category that counts is the one your health care professional assigns after reviewing the pattern. A chart tells you which range a number falls into. It does not tell you what condition you have.

If you want to use the category words yourself, use them the way health care professionals do. "My home average this week was 133 over 81, which is in the stage 1 range" is accurate and useful. "I have stage 1 hypertension" is a conclusion that needs a health care professional's review of repeated readings.

Home readings use slightly different lines

If you measure at home, you may notice that some charts list a different threshold for home readings. The 2025 guideline handles this with a correspondence table. At the lower end there is no difference: an office reading of 130/80 corresponds to a home reading of 130/80. At the stage 2 line the two diverge a little. An office reading of 140/90 corresponds to a home average of about 135/85, and an office reading of 160/100 corresponds to a home average of about 145/90. Relaxed home readings tend to run a bit lower than office readings, so the home lines sit a few points lower.

You do not need to memorize this. In practice, that a home average of 136/86 is not "almost stage 1." It corresponds roughly to the office stage 2 line and belongs in front of your health care professional along with your written log. A separate article in this series explains how home, office, and ambulatory monitoring differ and how many readings make a reliable average.

When a reading is 180/120 or higher

The two severe ranges sit above stage 2 and work differently from the rest of the chart. Here the question is not which category you are in but what to do in the next few minutes. The American Heart Association's instructions, reviewed August 14, 2025, are specific.

If your monitor shows 180/120 or higher, meaning a top number of 180 or higher or a bottom number of 120 or higher, wait at least one minute and take the reading again. If the second reading is still that high and you have no symptoms, the AHA calls this severe hypertension. It usually does not require a hospital, but you should contact your health care professional as soon as possible rather than waiting for your next scheduled visit.

If the reading is 180/120 or higher and you have any of the following symptoms, do not wait to see whether it comes down on its own. Call 911. This is the range the guideline calls a hypertensive emergency, which means the pressure may be actively damaging the heart, brain, kidneys, or eyes.

1. 1 Chest pain.
2. 2 Shortness of breath.
3. 3 Back pain.
4. 4 Numbness or weakness.
5. 5 A change in vision.
6. 6 Difficulty speaking.

A reading far above your usual pattern with no symptoms is sometimes a measurement problem: a cuff that is too small, an arm resting below heart level, or a reading taken right after climbing the stairs. The one minute recheck is designed to catch some of that. It is not a reason to dismiss a repeat reading that stays at or above 180/120.

What a low reading means

The chart has a floor as well. The American Heart Association describes low blood pressure, or hypotension, as a reading below 90/60 mm Hg. Unlike the high categories, a low number by itself is usually not treated as a problem. The AHA notes that low blood pressure is generally not harmful unless it comes with symptoms that concern a health care professional. Many healthy people, especially those who are young, slim, or very active, run in this range without trouble.

Symptoms change the picture. Dizziness, lightheadedness, fainting, blurred vision, confusion, nausea, and unusual fatigue alongside a low reading are worth reporting. So is dizziness when you stand up, which can signal a drop in pressure on standing, called orthostatic hypotension. Mayo Clinic defines it as a fall of 20 mm Hg in the top number or 10 mm Hg in the bottom number within 2 to 5 minutes of standing, notes that it is common after age 65, and lists several blood pressure medicines among the causes. If that sounds familiar, do not stop or skip a medicine on your own. Call your care team and describe what you noticed. A health care professional may check your pressure sitting and then standing to see what is happening.

Why charts online disagree

Search for a blood pressure chart and you will find several that do not match. There are three main reasons.

The first is age. Before 2017, the United States used a different scheme with a category called prehypertension that covered 120 to 139 systolic or 80 to 89 diastolic, with stage 1 beginning at 140/90 and stage 2 at 160/100. The 2017 guideline replaced that system with the four categories above, and the 2025 guideline kept them. Some hospital and health system pages still display the older chart. If a chart uses the word prehypertension or starts stage 1 at 140, it is out of date for US readers, and a reading of 134/84 that it labels prehypertension is stage 1 under current US guidance.

The second is geography. The European Society of Cardiology's 2024 guideline uses three categories rather than four: non elevated (under 120 systolic and under 70 diastolic), elevated (120 to 139 systolic or 70 to 89 diastolic), and hypertension (140/90 or higher, confirmed). A reading of 134/82 is stage 1 hypertension on a US chart and elevated blood pressure on a European one. Same reading, different label. Neither guideline regards 134/82 as ideal, but if you read international health sites or compare notes with relatives abroad, the vocabulary will not line up. European home and ambulatory thresholds also differ slightly, with home hypertension set at 135/85 or higher and a 24 hour ambulatory average of 130/80 or higher.

The third is decoration. Some charts and some home monitors add color bands or labels such as "high normal" that no current guideline uses. Monitor makers choose which scheme a color indicator follows, so when comparing with the US categories, read the numbers and ignore the color.

Pregnancy uses its own lines

The standard chart does not apply during pregnancy. The American Heart Association's Go Red for Women guidance describes a healthy pregnancy reading as under 140/90 mm Hg. Hypertension in pregnancy is a top number of 140 or higher or a bottom number of 90 or higher. The severe range begins at 160 systolic or 110 diastolic, and a reading there is a reason to seek care right away. Call 911 if it comes with a severe headache, a change in vision, abdominal pain, chest pain, significant swelling, or shortness of breath.

Timing matters in pregnancy as well. High blood pressure diagnosed before pregnancy or before 20 weeks is called chronic hypertension. High blood pressure that first appears after 20 weeks is gestational hypertension. Preeclampsia is high blood pressure in pregnancy accompanied by other signs, such as protein in the urine. The AHA also advises anyone who had high blood pressure during pregnancy to have a reading checked within 3 to 10 days of going home after delivery. If you are pregnant or planning to be, ask your obstetric care team which numbers they want you to watch. The everyday chart is not the right yardstick.

Where the chart stops and your clinician starts

The chart answers one question: which range a given average falls into. It does not answer the questions that decide care. Whether you need treatment, what your personal goal should be, and how quickly to act depend on your overall cardiovascular risk, age, kidney function, diabetes, pregnancy, other medicines, and how well you tolerate lower pressures. For most adults being treated, the 2025 guideline recommends a goal below 130/80 mm Hg, with adjustments for situations such as limited life expectancy, residence in a care facility, and pregnancy. Two people with the same average of 134/82 can reasonably leave the office with different plans. A separate article in this series explains why a category chart is not a care plan, and another offers questions to ask about your own target.

What you can do with the chart is prepare. A few habits make the conversation with your care team faster and more accurate.

1. 1 Write down every reading with the date, time, and which arm you used. A paper or phone log you can hand over is easiest to review.
2. 2 Report averages, not single readings. Two readings in the morning and two in the evening for a week gives your health care professional a picture; one alarming number gives them a puzzle.
3. 3 Name the range using the current US lines and say how you measured. "My seven day home average was 138 over 88, seated after five minutes of rest" tells a health care professional far more than "my pressure is high."
4. 4 Know the two numbers that change the timeline: 180/120 or higher (recheck after a minute, then call, or call 911 with symptoms) and below 90/60 with dizziness, fainting, or confusion (report it promptly).
5. 5 Ask which category your health care professional believes you are in and why. If the answer differs from your own reading of the chart, the reason is usually the average, the setting, or a pregnancy or kidney related threshold, and it is worth understanding.

Nearly half of US adults have high blood pressure by the current definition, and the Centers for Disease Control and Prevention estimates that about 1 in 6 of them does not know it. Knowing which range your average falls in, and knowing that the range is a starting point rather than a verdict, puts you well ahead of that group.