Normal blood pressure: the table, what changes with age and how to measure it at home

“Normal blood pressure” is one of the most frequent health searches in Mexico, and it almost always starts with a reading: 135/88 at the pharmacy, 128/82 at home, 150/95 at the clinic. The underlying question is whether that number is fine for you, and the short answer is that a single number is not enough to know. This text explains what the two figures measure, which table the guidelines use, why the online “table by age” comes from none of them, and how to measure at home so the reading counts. By the way: blood pressure and arterial tension are the same thing.

First, what cannot wait. If your pressure reads above 180 systolic or above 120 diastolic and you also have chest pain, shortness of breath, back pain, numbness or weakness, vision changes or trouble speaking, do not measure again and do not keep reading: it is an emergency and you need to call emergency services now.^[5] If it reads the same but you have no symptoms, wait at least one minute, measure again and, if it is still that high, contact your doctor today.^[6]

What the two numbers mean

Blood pressure is written as two figures, for example 120/80, and measured in millimetres of mercury (mmHg). The first, the systolic, is the pressure the blood exerts against the artery walls when the heart beats. The second, the diastolic, is the pressure while the heart rests between beats.^[5] Both count, and when they fall into different categories, the classification follows the higher of the two.^[1]

There is a useful nuance for anyone past 50: from that age systolic says more about cardiovascular risk, because the arteries become stiffer and the top number tends to rise.^[5] The European guidelines describe it this way: systolic increases progressively with age, while diastolic rises only until age 50 to 60.^[1] That explains a frequent combination in older people: high systolic with normal diastolic, which the guidelines call isolated systolic hypertension.^[1]

The normal blood pressure table according to the guidelines

There is not one table but two big families. The first is the European one, updated by the European Society of Hypertension in 2023, and it is the same logic the official Mexican standard follows.^[1][9] Its categories are these, and they are the same for any adult, whether 25 or 75:^[1]

The Mexican standard NOM-030-SSA2-2009 uses those same cut-offs, calls the band of 130 to 139 systolic or 85 to 89 diastolic “borderline”, and defines hypertension from 140/90.^[9] It is the official reference for screening in Mexico, and it asks for a measurement every three years in adults and twice a year from age 65.^[9]

The second family is the US one. The 2017 guideline of the American College of Cardiology and the American Heart Association lowered the threshold and simplified the categories:^[4]

The practical difference lies in the band of 130 to 139 systolic or 80 to 89 diastolic: for the European guideline and the Mexican standard it is “high-normal” or “borderline”, for the US one it is already stage 1 hypertension.^[2] Neither is wrong; they measure the same thing and place the label in a different spot. What they all agree on is what matters to you: below 120/80 is optimal ground, and from 140/90 at the clinic all of them speak of hypertension.^[1][4][9]

Does normal blood pressure change with age?

If you searched for “normal blood pressure by age”, you will have found tables with one row per decade, where 140/90 appears as “normal” at 60. Those tables come from no current clinical guideline: the 2023 European one, the 2017 US one and the Mexican standard use the same cut-offs for all adults.^[1][4][9] What does change with age is the probability of having high pressure. Age is one of the recognised risk factors,^[7] systolic tends to rise decade after decade^[1] and, worldwide, about 1.4 billion adults aged 30 to 79 were living with hypertension in 2024, 44 % of them without knowing it.^[7]

There is one place where age does enter the guidelines, and it should not be confused with the table: treatment targets. The 2023 European guideline proposes bringing pressure below 130/80 in most adults already on medication, below 140/80 between ages 65 and 79, and to a systolic between 140 and 150 in people aged 80 or older.^[2] In other words, what is relaxed with age is how far to lower pressure with medicines in someone who already has hypertension, not the point at which a reading stops being normal. The Mexican standard keeps the same target as in younger people, with a transitional target below 160 systolic when it starts very high.^[9]

Why a single reading says little

Pressure changes throughout the day, with effort, stress and even conversation. That is why no guideline diagnoses with one figure: the WHO asks for readings of 140/90 or more on two different days,^[7] the Mexican standard bases the diagnosis on the average of at least three measurements taken two weeks after the first detection,^[9] and the European guideline asks for confirmation with out-of-office measurements or a second visit.^[3]

Two situations with their own names explain why the pharmacy reading and the home reading do not match. In white-coat hypertension pressure comes out high at the clinic and normal outside it; in masked hypertension the opposite happens: normal in front of the doctor, high at home.^[3][4] Both are discovered by measuring at home for several days.

Besides, many things raise a reading temporarily without your usual pressure having changed:

• Coffee, tobacco or exercise in the previous 30 minutes.^[6]
• A full bladder, talking during the measurement or not having rested five minutes.^[4]
• Crossed legs, an unsupported back or an arm hanging below heart level.^[4]
• A cuff over clothing or of the wrong size for your arm.^[6]
• A wrist or finger device, which gives less reliable readings than an upper-arm one.^[6][9]
• Medicines and substances that raise pressure: decongestants, anti-inflammatories (NSAIDs), oral contraceptives, corticosteroids, some antidepressants and alcohol.^[4]

How to measure blood pressure at home

The device: automatic, with an upper-arm cuff (not wrist or finger) and validated, that is, tested against an accuracy standard; the AHA points to a public registry of validated devices to check before buying.^[6] The Mexican standard agrees: it accepts electronic devices that measure on the upper arm and advises against wrist and finger ones.^[9] Measure the circumference of your arm and choose the matching cuff size; the wrong size gives inaccurate readings.^[6]

1. Prepare: no coffee, tobacco or exercise in the previous 30 minutes, and empty your bladder.^[6]
2. Sit and wait five minutes in silence, without your phone, back supported, feet flat on the floor and legs uncrossed.^[4][6]
3. Bare arm, supported on a table, with the cuff at heart level and its lower edge just above the elbow.^[6]
4. Two readings one minute apart, without talking or moving between them, and write down both.^[6]
5. Morning and evening: the morning one before breakfast and medicines, but not right on waking; the evening one before dinner.^[3][4]
6. Seven days in a row: the European guideline accepts a minimum of three and recommends reaching seven if the average lands close to the threshold; the result is the average of all readings.^[3]

You can use either arm: readings rarely differ much between the two.^[6] If you keep measuring after that week, the US guideline suggests a full week before each appointment.^[4]

At home the threshold is lower

Home readings are usually somewhat lower than clinic ones, and the guidelines take this into account: a home average of 135/85 equals 140/90 at the clinic, and it is the cut-off for speaking of hypertension with home measurements.^[3][4] This equivalence table from the US guideline helps translate:^[4]

When to repeat and when to consult

With the week’s average in hand, the decision becomes simpler:

• Below 120/80 at home: optimal ground. Repeat the week of measurements once or twice a year and keep the log. The Mexican standard asks for screening every three years in adults.^[9]
• Systolic 120 to 134, or diastolic 80 to 84: not hypertension under the European definition, but for the US guideline it is already “elevated” or “stage 1” from 130/80.^[1][4] It is the band where context weighs most: weight, salt, alcohol, family.^[7] Bring the log to your next appointment.
• Home average of 135/85 or more, or repeated clinic readings of 140/90 or more: it is the hypertension threshold in any guideline.^[3][4][9] Not an emergency, but an appointment in the coming weeks, with the seven-day log.
• Above 180/120 at any time: wait at least one minute and repeat. Without symptoms, contact your doctor today; with symptoms, emergency.^[6]

Warning signs

Ordinary high blood pressure cannot be felt: most people with hypertension have no symptoms at all, and the only way to know is to measure it.^[7][8] That dismantles the myth of “if my head hurts or my nose bleeds, it is the pressure”: except in very marked rises, generally 180/120 or more, a headache usually has another explanation, as we explain in this text on frequent headaches.^[7] What does demand immediate action is the combination of a very high figure with symptoms:

• Pressure above 180/120 with chest pain or tightness.^[5]
• Pressure above 180/120 with shortness of breath, back pain, numbness, weakness or trouble speaking.^[5]
• Pressure above 180/120 with vision changes, severe headache or confusion.^[5][7]
• The same figure without symptoms is not an emergency, but it is a call to your doctor the same day, after repeating the measurement.^[6]
• In pregnancy, any reading of 140/90 or more is discussed with the doctor without waiting for the seven-day log: pregnancy is among the conditions that raise the risk.^[8]

What to bring to the doctor

An appointment about blood pressure is decided in minutes, and what you bring changes the quality of that decision.

1. The seven-day log: date, time, both readings of each session and the average. If your device stores readings, bring it.^[6]
2. The device itself, at least once a year, to compare it with the clinic one.^[6]
3. List of medicines and supplements, including decongestants, anti-inflammatories, contraceptives and corticosteroids.^[4]
4. Context: weight and waist, how much salt and alcohol, physical activity, whether you smoke, family history of hypertension, pregnancy.^[7][8]
5. Previous results for glucose, cholesterol and creatinine, if you have them. If any came out altered, see high creatinine and high cholesterol.
6. Resting heart rate, if your device or your watch records it: here we explain how to read it.