High blood pressure
High blood pressure usually has no symptoms and is shown only by measuring it. This page explains what the numbers say, how it is checked and controlled, and when to act urgently.
What is high blood pressure?
Each time the heart beats, it sends blood through the arteries under pressure. If this pressure stays high all the time, it strains the arteries, heart, brain, kidneys and eyes. The NHS says that if untreated it raises the risk of heart disease, heart attack, stroke, heart failure, kidney disease and vascular dementia.
A blood pressure reading has two numbers, for example 130 over 80. The upper number (systolic) is the pressure when the heart pumps, and the lower number (diastolic) is the pressure between beats.
The important point is that high blood pressure usually has no symptoms. The NHS says it may sometimes cause headaches, blurred vision or chest pain, but often it does not.
Who should have their blood pressure checked?
The NHS lists these as reasons for higher risk: older age, a close relative with high blood pressure, a salty diet, being overweight, smoking, drinking a lot of alcohol and long-term stress. The WHO also lists diabetes, kidney disease, a family history and age over 65.
So if you have any of these, or you are over 40 and have not had your pressure checked for more than five years, have it measured (NHS). The WHO recommends regular measurement. For how to measure at home, see the guide “Measuring blood pressure at home”.
How is it checked?
With a cuff around the upper arm. If the first reading is high, the NHS says you may be asked to:
- Check your pressure regularly at home for a few days
- Come back for another check in a few days or weeks
- Wear a portable 24-hour monitor
The WHO says the diagnosis is made when a reading of 140/90 or more is recorded on two different days. So seeing one high reading is not a diagnosis and should not cause fear or the start of a medicine. But do not ignore it either.
The WHO says that even with a home device, an assessment by a healthcare professional is important to judge overall risk and related conditions. Which further checks the doctor thinks necessary depends on your situation.
What does treatment look like in general?
The basis of treatment is lifestyle change. The WHO and the NHS both stress a low-salt, balanced diet, regular physical activity, losing weight if overweight, stopping smoking and cutting down on alcohol.
For medicines, the NHS says a doctor usually prescribes them when the pressure is very high, the risk of heart attack or stroke is higher, or it is still high despite lifestyle changes. There are different medicines, and the choice among them depends on the pressure reading, age and other factors. Most are taken once a day, and sometimes more than one medicine is needed.
The WHO gives two targets: below 130/80 for people with cardiovascular disease, diabetes, chronic kidney disease or high risk, and below 140/90 for most others. Your own target is set by your doctor.
Do not start, stop or adjust blood pressure medicine yourself. Do not share it with others.
What can you do yourself?
- Measure your pressure correctly and regularly, and write it down. Write the numbers without rounding and bring them with you.
- Cut down on salt. The WHO gives less than 2 grams a day.
- Be active. The NHS gives at least 150 minutes of exercise a week. If you have heart disease or are worried, talk to a doctor before you start.
- Cut down on alcohol and caffeine, and stop smoking.
- Take your medicines as directed and do not miss follow-up appointments.
- If medicine side effects bother you, tell your doctor or pharmacist. Do not stop on your own.
When to seek urgent care
The WHO says very high blood pressure (usually 180/120 or more) can cause a severe headache, chest pain, dizziness, breathlessness, nausea, vomiting, changes in vision, anxiety, confusion, ringing in the ears, nosebleeds or an irregular heartbeat, and needs urgent care.
Call 115 (Iran’s emergency number) and do not wait for an appointment if:
- You have sudden chest pain or pressure that does not go away, or that spreads to the arm, neck, jaw, belly or back, or comes with sweating, nausea, dizziness or breathlessness
- Your reading is very high and you have any of the symptoms above
- One side of the face has suddenly dropped, an arm has become weak, your speech is confused or your vision has suddenly become blurred
Do not drive yourself.
If you often have headaches or blurred vision, or chest pain that comes and goes, do not put off a medical check, and act as soon as you can (NHS).
Symptoms and treatment plans differ from patient to patient. Talk to a doctor about your own situation.
Frequently asked questions
High blood pressure has no symptoms? Then how will I know?
Both the NHS and the WHO say high blood pressure usually has no symptoms and the only reliable way to know is to measure it. This is why many people do not know they have it. Only a measurement with a device can show it.
What number counts as high?
The NHS says a reading of 140 over 90 or more taken by a healthcare professional, or 135 over 85 or more at home, is usually counted as high. The WHO defines high blood pressure as 140/90 or more and requires a high reading on two different days for a diagnosis. One high reading is not a diagnosis.
If my blood pressure was high once, should I start medicine?
No. Starting, changing or stopping a medicine is the doctor's decision. The NHS says the doctor may ask you to check your pressure at home for a few days, come back for another check in a few days or weeks, or wear a 24-hour monitor.
Do I have to take blood pressure medicine for life?
This depends on each patient and you need to ask your own doctor. The NHS says most blood pressure medicines are taken once a day and sometimes more than one medicine is needed. The WHO also says to take medicines as directed, not to stop them and not to share them. Never stop or cut down a medicine on your own.
How much should I cut down on salt?
The WHO recommends less than 2 grams of salt a day. The NHS also advises cutting down on salt. If you have kidney or heart disease, ask your own doctor what amount is right.
My blood pressure has suddenly gone very high. What should I do?
If the reading is very high (in the WHO source, about 180/120 or more) and comes with symptoms such as a severe headache, chest pain, breathlessness, blurred vision, confusion or dizziness, it needs urgent care. Call 115 (Iran's emergency number).