Blood pressure 135/85 – still normal or already too high?

135/85 is one of the most frequently looked-up blood pressure readings of all. There is a reason for this: it lies exactly on a threshold – and depending on where you measured, the answer is different.

The short answer

Measured at the doctor’s surgery: high normal. Not yet a diagnosis of hypertension, but no longer in the target range either.

Measured yourself at home: this is already hypertension. The threshold for home measurement is 135/85 mmHg – so you are right on it.

The same two numbers, two different classifications. This is not a contradiction; there is a sober reason for it.

Why stricter thresholds apply at home

At the surgery, a certain amount of tension is always measured too – the journey there, the waiting room, the situation itself. Readings there are higher on average than in everyday life. To arrive at the same medical conclusion, the thresholds for self-measurement were set correspondingly lower: 140/90 at the surgery roughly corresponds to 135/85 at home.

Anyone who judges their home readings against the surgery chart therefore systematically rates themselves as less at risk than they are. You will find the full comparison of both charts in Blood pressure chart: what your numbers mean.

This threshold does not change with age – why the age charts in circulation are misleading is explained in Blood pressure chart by age.

Before you classify yourself: was the measurement clean?

With a reading that sits so precisely on the threshold, measurement technique decides the classification. A few millimetres of mercury in one direction or the other add up quickly here:

• Five minutes of rest beforehand – without it, you are measuring the last flight of stairs, not your blood pressure.
• Cuff at heart level – ten centimetres below adds around 7.5 mmHg too much.
• Correct cuff size – a cuff that is too small pushes the reading up.
• Don’t talk, don’t cross your legs, keep your back supported.
• No coffee and no cigarettes in the 30 minutes beforehand.

All seven common mistakes are covered in Measuring blood pressure correctly.

A single reading means nothing yet

Blood pressure fluctuates continuously with the rhythm of your breathing. Two measurements taken two minutes apart regularly give different numbers – both measured correctly. The reason for this is explained in Why your blood pressure is different every time you measure it.

So if you have measured 135/85 once, you still know nothing about your blood pressure. You only know after a measurement week: seven days, two measurements each morning and evening, leave out the first day, calculate the average from the rest.

If this weekly average is 135/85 or above, it should be assessed by a doctor. If it is below – say 128/82 – the single measurement was a snapshot at the upper end.

What the gap between the numbers also reveals

135 minus 85 gives a pulse pressure of 50 mmHg. That is within the typical range of about 40 to 50 and is unremarkable. What this third number tells you and when it becomes important is explained in Pulse pressure: what the gap between your blood pressure readings reveals.

What makes sense now

1. Measure cleanly for a week and write everything down – including the uncomfortable readings.
2. Calculate the average and compare it with the home measurement threshold of 135/85.
3. Take the sheet with you to your next doctor’s appointment. Seven documented days are worth much more for the assessment than one measurement at the surgery.
4. Don’t change anything about existing medication.

A reading at this threshold is no cause for alarm, but a good reason to find out for certain. It is precisely in this range that exercise, salt, weight and sleep can often still make a big difference – which of these apply in your case is something for your doctor to assess.

When you shouldn’t wait

• If individual readings are repeatedly above 180/110 mmHg
• If you have headaches, visual disturbances, shortness of breath, dizziness or a racing heart
• If you are pregnant – different standards apply in pregnancy, and 135/85 already needs to be checked there

In the event of a sudden severe headache, chest pain, speech or vision problems, or one-sided paralysis: call the emergency services immediately on 112 (the European emergency number).