Blood Pressure Checker — NHS Blood Pressure Chart UK

The NHS says ideal blood pressure is between 90/60 mmHg and 120/80 mmHg. High blood pressure is 140/90 mmHg or above (measured at a GP surgery). Low blood pressure is below 90/60 mmHg. The range between 121/81 and 139/89 is considered slightly elevated but not yet classified as high blood pressure.

Blood pressure is measured as two numbers. The top number (systolic) is the pressure when your heart beats and pumps blood. The bottom number (diastolic) is the pressure between beats when your heart rests. A reading of 120/80 means a systolic of 120 mmHg and a diastolic of 80 mmHg.

The NHS defines high blood pressure (hypertension) as 140/90 mmHg or above when measured at a surgery. For home readings, 135/85 or above is considered high. Stage 1 hypertension is 140–159/90–99. Stage 2 is 160/100 or above. A reading of 180/120 or above is a hypertensive crisis requiring urgent medical attention.

If your reading is in the high range (140/90 or above), speak to your GP. They will take multiple readings over time before diagnosing hypertension. You can also make lifestyle changes straight away: reduce salt intake, exercise regularly (at least 150 minutes per week), reduce alcohol, stop smoking, and maintain a healthy weight. Do not stop any blood pressure medication without speaking to your doctor.

Yes. Home blood pressure monitors are widely available and recommended by the NHS for people who have been diagnosed with high blood pressure or are at risk. Use a validated upper-arm monitor, take readings at the same time each day, and take two readings one minute apart. Record your blood pressure each time in a diary or app — your GP needs the pattern over days, not a single number. Many pharmacies also offer a free blood pressure test.

In most cases the exact cause is unknown — this is called primary or essential hypertension. Risk factors include age, family history, being overweight, eating too much salt, drinking too much alcohol, smoking, lack of exercise, and long-term stress. In some cases high blood pressure is caused by an underlying condition such as kidney disease, diabetes, or certain medications.

A hypertensive crisis is a reading of 180/120 mmHg or above. If you have symptoms such as chest pain, shortness of breath, severe headache, blurred vision, or confusion alongside this reading, call 999 immediately. If you have no symptoms, sit and rest for five minutes, then take the reading again. If it remains at 180/120 or above, contact your GP or call 111.

Blood pressure is measured in millimetres of mercury (mmHg) using a blood pressure monitor (sphygmomanometer). An inflatable cuff is placed around your upper arm and inflated to temporarily stop blood flow. As the cuff deflates, the monitor detects the pressure at which blood starts flowing again (systolic) and the resting pressure (diastolic).