Understanding Blood Pressure: What Your Numbers Mean
Blood pressure has two numbers and both matter. Learn what they mean, how to measure at home the right way, and the daily habits that lower them.
High blood pressure is often called the silent problem because most people feel nothing while it slowly strains the heart, brain, and kidneys. The good news is that it is easy to measure and often controllable.
What the two numbers mean
A reading like 120/80 has two parts:
- Systolic (the top number): the pressure in your arteries when your heart beats and pushes blood out.
- Diastolic (the bottom number): the pressure when your heart rests between beats.
Both are measured in millimetres of mercury, written mmHg.
What counts as high?
Doctors and organisations use slightly different cut-offs, which is why you may see different advice. The American Heart Association describes:
- Normal: below 120/80
- Elevated: 120 to 129 over less than 80
- High, stage 1: 130 to 139 or 80 to 89
- High, stage 2: 140/90 or higher
- Crisis: higher than 180 and/or 120. This needs urgent medical help.
The World Health Organization defines hypertension as a repeated reading of 140/90 or above. A single high reading does not mean you have it, since blood pressure changes through the day. Doctors look at repeated readings.
How to measure at home the right way
Prepare
Avoid caffeine, smoking, and exercise for 30 minutes. Use the toilet first.
Sit properly
Sit with your back supported, feet flat on the floor, legs uncrossed.
Position your arm
Rest your arm on a table so the cuff is at heart level. Use a cuff that fits.
Rest and stay quiet
Sit still for 5 minutes. Do not talk during the measurement.
Measure twice
Take two readings a minute apart and note both. Record them at the same time each day.
Daily habits that help
- Cut salt. The WHO recommends under 5 grams of salt a day, about one teaspoon. Pickles, papad, chips, and packaged foods hide a lot.
- Eat more potassium-rich foods such as bananas, coconut water, beans, and leafy greens.
- Move regularly. About 150 minutes of brisk activity per week helps lower pressure.
- Keep a healthy weight, limit alcohol, and do not smoke.
- Sleep and stress count too. Poor sleep and constant stress both raise pressure.
What most people miss
- "White coat" effect. Some people have higher readings at the clinic only because they feel nervous. Home readings help sort this out.
- Never stop medicines on your own. If you are prescribed blood pressure tablets and feel fine, that usually means they are working.
