Blood Pressure Categories
The worse of the two numbers decides — not the average.
Reading your result
Fill in every field and the steps will be spelled out here.
How it is calculated
Classification takes the worse reading, not the average. At 135/78 the systolic sits in stage 1 while the diastolic is normal — the reading is stage 1. One elevated number is enough to matter.
A single measurement decides nothing. Blood pressure swings 20mmHg or more with time of day, posture, stress, caffeine and recent activity, and white-coat elevation in clinic is common. Repeated home readings across several days are what a clinician works from.
Technique moves the number. Sit quietly for five minutes, keep the arm at heart height, and use a cuff that fits — an undersized cuff reads high.
Above 180 systolic or 120 diastolic may be an emergency, particularly alongside headache, visual disturbance or chest pain. Seek care immediately.
Frequently asked questions
Home and clinic readings differ.
Common. White-coat hypertension raises clinic readings, and masked hypertension does the reverse. Bringing a series of home readings to an appointment is genuinely useful.
When should I measure?
Within an hour of waking after emptying the bladder, and again before bed. Keep the time and posture constant so readings are comparable, and avoid measuring straight after coffee, smoking or exercise.
Only my diastolic is high.
That still places you in the category, since the worse number governs. Isolated diastolic elevation is more common in younger adults and should not be ignored.
This maps entered numbers onto standard categories and is not a diagnosis. Diagnosis and treatment follow repeated measurement and clinical assessment. Readings above 180 systolic or 120 diastolic warrant immediate medical attention.