What is normal blood pressure?

For most adults, normal blood pressure is less than 120/80 mmHg, according to the American Heart Association. A systolic of 120 to 129 with a diastolic under 80 counts as elevated, and 130/80 or higher falls into hypertension. The NHS describes a healthy range of roughly 90/60 to 120/80 mmHg.

That single line answers the question, but “what is normal blood pressure” deserves a bit more than a number. Blood pressure moves through the day, guidelines differ slightly between countries, and one reading on one morning tells you far less than a pattern over a few weeks. Here is how to read your own numbers with confidence.

What is normal blood pressure for an adult?

Every reading has two numbers, both measured in millimetres of mercury (mmHg).

• Systolic is the top number. It is the pressure in your arteries while your heart beats.
• Diastolic is the bottom number. It is the pressure between beats, while your heart refills.

So a reading of 118/76 means a systolic of 118 and a diastolic of 76. Under American Heart Association and American College of Cardiology guidance, that reading is normal, because both numbers sit below the 120 and 80 lines.

The word “normal” is doing precise work here. It does not mean average, and it does not mean typical for your age group. It means the range where cardiovascular risk is lowest. Plenty of people run higher than 120/80 without feeling any different, which is exactly why blood pressure is worth measuring rather than guessing.

The full blood pressure categories

The American Heart Association sets out five adult categories:

Category	Systolic (mmHg)		Diastolic (mmHg)
Normal	less than 120	and	less than 80
Elevated	120 to 129	and	less than 80
Hypertension stage 1	130 to 139	or	80 to 89
Hypertension stage 2	140 or higher	or	90 or higher
Hypertensive crisis	higher than 180	or	higher than 120

Two details trip people up.

First, the joining word matters. Normal and elevated both require and, so both numbers have to qualify. Stage 1 and stage 2 use or, so a single number is enough to move you up.

Second, when your two numbers land in different bands, the higher category is the one that counts. A reading of 124/84 has a systolic in the elevated range and a diastolic in the stage 1 range, so it is classed as stage 1 hypertension. Our guide to understanding your blood pressure readings walks through more worked examples.

Normal blood pressure in the UK and the US

If you have seen two different answers online, this is usually why. The two systems draw the line in different places.

The NHS treats a clinic reading of 140/90 mmHg or higher as high blood pressure, or a home average of 135/85 or higher. It describes an ideal reading as between 90/60 and 120/80 mmHg, and calls anything between 120/80 and 140/90 a sign you could be heading towards high blood pressure without some changes.

The American Heart Association lowered its thresholds in 2017, so hypertension in the US starts at 130/80. A reading of 134/86 would be labelled stage 1 hypertension in the US and “slightly raised, keep an eye on it” in the UK.

Neither system is wrong. They are drawing the line at different points on the same continuous risk curve. The practical takeaway is identical either way: lower is generally better, and the further you drift above 120/80, the more it is worth doing something about.

Does normal blood pressure change with age?

Blood pressure tends to rise with age as arteries stiffen, so the average reading in a group of 70 year olds is higher than in a group of 30 year olds. That is a description of what happens, not a target.

The American Heart Association applies the same categories to all adults. There is no separate, more forgiving definition of normal once you pass 60, and a reading of 145/90 is stage 2 hypertension whether you are 35 or 75. If you want to see how readings typically distribute across age groups, our normal blood pressure by age chart lays it out, with the same caveat attached.

Children are the genuine exception. Under the American Academy of Pediatrics clinical practice guideline, blood pressure in under 18s is assessed against percentile charts that account for age, sex and height rather than a single fixed threshold, which is why paediatric readings should always be interpreted by a clinician.

Why one reading does not define your normal

Blood pressure is not a fixed trait like your blood type. It changes minute to minute in response to activity, caffeine, conversation, a full bladder, a cold room, stress, and time of day. The American Heart Association notes that blood pressure follows a daily rhythm, typically dipping overnight and rising in the hours around waking.

A few things that commonly push a single reading up:

• Measuring within 30 minutes of coffee, a cigarette, exercise or a large meal
• Talking during the measurement
• Sitting with your back unsupported, legs crossed, or your arm hanging below heart level
• A cuff that is too small for your arm
• Being at the doctor’s surgery, which is common enough to have its own name, white coat hypertension

This is why clinicians diagnose on averages, not one-offs. To find your real normal, sit quietly for five minutes, sit with your back supported and feet flat on the floor, rest your arm at heart level, then take two or three readings a minute apart and average them. Do that at roughly the same time each day for a week or two. Our full guide to measuring blood pressure at home covers the technique step by step.

When to see a doctor

Most blood pressure questions are not urgent, but a few are.

Call emergency services immediately if a reading is higher than 180 systolic, or higher than 120 diastolic, and comes with chest pain, shortness of breath, weakness or numbness, vision changes, difficulty speaking, or a severe headache. The American Heart Association advises that if you record a reading that high without those symptoms, wait five minutes, measure again, and contact your doctor without delay if it stays there.

Book an appointment if your home average sits at or above 130/80 mmHg, if it is climbing over weeks, or if it is consistently below 90/60 mmHg and you feel dizzy, faint or unwell.

Keep your routine checks if you have already been diagnosed with high blood pressure, even when you feel completely fine. High blood pressure usually has no symptoms at all, which is the whole reason it gets measured.

This guide is general information and does not replace personalised medical advice.

Track your BP free in CardioVibe

Your normal is a pattern, not a number you catch once. You can track your blood pressure free in CardioVibe, watch your average settle over time, and bring a clear record to your next appointment. It is there to support your care, not replace it.

Frequently asked questions

Is 120/80 normal blood pressure?

Not quite, under current US guidance. Normal requires a systolic below 120 and a diastolic below 80, so 120/80 sits right on the boundary. The American Heart Association would class it as elevated. The NHS still treats 120/80 as the top of its healthy range. In practice it is a good number that is worth keeping from drifting higher.

What is a normal blood pressure reading by age?

The American Heart Association uses the same categories for all adults, so normal is less than 120/80 mmHg at 25 and at 75. Average readings do rise with age, but that reflects what commonly happens rather than what is healthy.

Is low blood pressure a problem if I feel fine?

The NHS defines low blood pressure as under 90/60 mmHg. On its own, in someone with no symptoms, it is often not a concern and can simply be your normal. It is worth investigating if it comes with dizziness, fainting, blurred vision, nausea or unusual tiredness, or if it drops suddenly.

How many readings do I need before I know my normal?

Clinicians generally want a week or two of home readings, taken twice a day, before drawing conclusions. Averaging two or three measurements at each sitting and logging them consistently gives a far more reliable picture than any single number.

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Last reviewed: August 2026

Sources: American Heart Association (Understanding Blood Pressure Readings; Blood Pressure Categories chart); American College of Cardiology and American Heart Association 2017 hypertension guideline; American Academy of Pediatrics (Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents); UK National Health Service (Blood pressure test; High blood pressure; Low blood pressure).