In short
Blood pressure is the force of blood pushing against the walls of your arteries. When it stays high, the heart has to work harder and the arteries can be damaged over many years — usually without any symptoms. Knowing your numbers and keeping them under control is one of the most effective ways to protect your heart.
What the two numbers mean
A reading is written as two numbers, for example 120/80 mmHg. The first (systolic) is the pressure when the heart squeezes; the second (diastolic) is the pressure when it relaxes between beats. Your clinician will explain what your own readings mean and what target is right for you.
Why it is often missed
Most people with high blood pressure feel well. The only reliable way to know is to have it measured, so regular checks matter even when you have no symptoms.
What raised pressure does to the heart
Pumping against higher pressure can make the heart muscle thicken and stiffen over time. Raised pressure also contributes to narrowing of the arteries and increases the risk of heart attack, heart failure, atrial fibrillation and stroke.
Measuring at home
If your clinician suggests home monitoring, these general tips help make readings more reliable:
- Use a validated upper-arm monitor with a cuff that fits your arm
- Sit quietly for about five minutes first, back supported and feet flat on the floor
- Rest your arm at heart level and do not talk during the reading
- Write down each reading, with the date and time, and bring the record to your appointment
Small changes that add up
Eating less salt, staying active, keeping to a healthy weight, limiting alcohol and not smoking all help. These measures support — but do not replace — any medicine your clinician prescribes. Do not stop or change a blood pressure medicine without speaking to the clinician who prescribed it.
When to seek urgent help
A high reading together with chest pain, a severe headache, changes in vision, weakness on one side of the body or difficulty speaking needs emergency medical care immediately.
Questions to ask your clinical team
- What blood pressure target is right for me?
- Should I measure my blood pressure at home, and how often?
- Has high blood pressure affected my heart, and would any test help show this?
Common questions
Is it normal for readings to vary?+
Yes. Blood pressure changes throughout the day. Your clinician will look at the overall pattern rather than a single reading.
Can I stop my medicine once my readings are normal?+
Not on your own. Normal readings often mean the medicine is working. Discuss any change with the clinician who prescribed it.
Sources and further reading
- NHS — High blood pressure
- NHS — Blood pressure test
- World Health Organization — Hypertension fact sheet
General patient education written in plain language and informed by the sources above. It is not a substitute for an individual assessment, and does not describe practice-specific fees, referral rules or preparation — please confirm these with the practice.