High blood pressure

What is blood pressure?

With every beat the heart pushes blood into the arteries, and the arteries hold pressure against it. This pressure is given as two numbers: the top number (pressure as the heart beats) and the bottom number (pressure between beats). The UK’s National Health Service (NHS) notes that the first number is always the larger one, for example 130 over 80.

The NHS counts blood pressure as high when it is 140/90 or more in a clinic or other healthcare setting and 135/85 or more at home. The home threshold is slightly lower, so the same number does not mean the same thing in the two places. The 2024 European Society of Cardiology (ESC) guideline also suggests confirming high blood pressure with out-of-office readings (home or 24-hour) alongside the clinic reading. The final decision is the doctor’s.

A diagnosis is not made from one high reading. Stress, the visit itself, cold weather or coffee may have pushed it up. That is why a doctor usually repeats the measurement.

It usually has no symptoms

The NHS says high blood pressure usually causes no symptoms, and only rarely brings headaches, blurred vision or chest pain. Feeling well is therefore no proof that your pressure is normal. If you are 40 or older and have not had your blood pressure checked in the last five years, the NHS recommends getting it measured.

Who is more at risk?

According to the NHS: older age, a family history of high blood pressure, a high-salt diet, being overweight, smoking, heavy drinking and long-term stress. Each of these only raises the risk.

Why does it matter?

The NHS says untreated high blood pressure strains the blood vessels, heart, brain, kidneys and eyes, and raises the risk of heart disease, heart attack, stroke, heart failure, kidney disease and vascular dementia. Even a small drop in blood pressure lowers the risk.

Measuring and diagnosis

A doctor measures blood pressure on more than one occasion. The NHS says that if the first reading is high, you may be asked to measure at home for a few days or wear a portable 24-hour monitor. The guide section “Measuring blood pressure at home” describes the right method.

Besides blood pressure, a doctor may ask for an ECG, blood and urine tests or other checks to see what the high pressure has done or whether there is another cause. This depends on the examination.

Treatment

Lifestyle. The NHS lists:

• A balanced diet and less salt (salty food and salt added at the table)
• Regular activity, at least 150 minutes a week
• Losing weight if you are overweight
• Limiting alcohol and caffeine (tea, coffee, cola)
• Stopping smoking

Medicine. The NHS says a doctor usually prescribes medicine if blood pressure is very high, if the risk of stroke or heart attack is high, or if lifestyle changes do not bring it down. The type depends on the blood pressure reading, age and the patient’s circumstances, and most medicines are daily tablets. Some people need more than one.

A simple rule: start or stop a medicine only with your doctor’s advice. The AHA says that even if your home readings are normal, you should not stop medicine without talking to your doctor. If you notice a side effect, tell your doctor, who will decide what to do.

High blood pressure, the heart and the blood vessels

High blood pressure is one of the main causes of coronary artery disease and heart failure. Some blood pressure medicines may also cause ankle swelling (NHS). If you have swollen legs and take medicine, tell your doctor and do not stop the medicine yourself.

When to get urgent help

• The NHS says that if you have sudden, lasting chest pain that is tight, pressing or burning, or pain spreading to the arm, neck, jaw, stomach or back, or pain with sweating, nausea, dizziness or shortness of breath, call 115 (the emergency number in Iran). If you are outside Iran, call your local emergency number.
• If your blood pressure is above 180/120 and you have chest pain, shortness of breath, weakness or numbness, a change in vision or trouble speaking, do not wait: call 115 (outside Iran, your local emergency number). If you have none of these, the AHA says to wait five minutes and measure again. If it is still very high, call a doctor straight away, and if you cannot reach a doctor, call the emergency number.
• Have repeated headaches, blurred vision or chest pain that comes and goes seen by a doctor the same day (the NHS treats these as urgent).