10 blood pressure facts

In this article we will describe 10 blood pressure facts. Let’s start with the basics.

1. What is blood pressure?

Blood pressure is the pressure of blood pushing against the walls of your arteries. Arteries carry blood from your heart to other parts of your body.

2. What do the two blood pressure numbers mean?

Blood pressure is measured using two numbers:

First number – called systolic blood pressure – measures the pressure in your arteries when your heart beats
The second number – called diastolic blood pressure – measures the pressure in your arteries when your heart rests between beats.

If the measurement reads 120 systolic and 80 diastolic, you would say, ‘120 over 80’, or write, ‘120/80 mmHg’.

3. What is normal blood pressure?

There is no such thing as ‘normal blood pressure’. But for most adults there is a normal range between 110/70 and 140/90.

“130/80 is a good average target for most patients, and 120/70 if you have diabetes.”

For most people, high blood pressure (BP) is ‘silent’, i.e. you cannot ‘feel’ whether it is high or low.

4. Is BP constant or does it vary?

Your blood pressure varies minute and minute, and hour by hour. For example, blood pressure follows a circadian rhythm; it increases on waking in the morning and decreases during sleeping at night. This is why it is important not to make a decision on a single reading of BP. Several measurements are required.

Circadian rhythm of BP

5. How is blood pressure affected by age, gender and ethnicity?

As you can see from these graphs for the USA, age, gender and ethnicity all affect blood pressure, in the following ways:

Age. Blood pressure goes up as you get older – e.g.
– 110/70 is normal if you are 20 years
– 150/80 is normal if you are 80 years
– Pulse pressure (the gap between systolic and diastolic blood pressure) gets wider as you age. It can be 40 mmHg at 20 years, and 80 mmHg at 80 years
Gender. Men have higher blood pressure than women
Ethnicity. Black people have higher blood pressure than white people.

Implication
It is important to have different blood pressure targets for people of different ages, gender and ethnicities.

6. How common is high BP?

High blood pressure (or hypertension) is one of the commonest long term conditions. In fact, 20% of the population have high blood pressure, and a third of people over the age of 55 years. Over 6 million adults take blood pressure tablets in the UK.

Why is high blood pressure important?
It is because it causes strokes, heart attacks and heart failure, which is why we treat it.

7. What causes high blood pressure, and what is secondary hypertension?

In 90% of people there is no underlying cause (apart from ageing, and being overweight or obese). This is called essential or primary hypertension. In 10% there is an underlying cause – like Chronic Kidney Disease, CKD) and problems with the adrenal gland – and this is called secondary hypertension. More on secondary hypertension here.

If there is a cause, treatment of that is very important, or it will be hard to control the BP.

So. How can I lower my blood pressure?

8. What things you can do to lower your BP?

Weight loss. For many patients with high BP, being overweight or obese is a major factor. In fact, for some patients, if you lose a significant amount of weight, your BP can return to normal. So, if requested by a doctor, start to lose weight and it will help alot.
Low salt diet – can also reduce BP.
Lifestyle changes – it is also good idea not to smoke, exercise and keep your alcohol consumption down.
Blood pressure machine. Buy a BP machine from any chemist or large supermarket or Amazon – prices vary, approximately £20-£40. ‘A&D’ is a good make. Take your own BP once a week until stable and below 140/90 every time, at home, GP or hospital. When stable, take it every three months.
What’s the cause? Make sure that your GP and/or hospital consultant looks for an underlying cause, if there is one. Treating that is as important as treating the BP.

9. What things the can my GP do?

GP. For most patients, a GP will be able to diagnose and treat hypertension, without referral to the hospital. If your GP is having problems with controlling your BP, it is a good idea to be referred to the nearest hospital hypertension unit.
GP Practice Nurse. Many GPs have a practice nurse that runs a ‘long-term condition’ clinic on their own. Ask for three monthly review there. Some of them work with a clinical pharmacist who can do a similar role.

10. If I need to go to hospital, how do I get referred and to where?

Hospital hypertension unit. Your GP can refer you to such a unit at your local hospital. You will see a senior doctor – either a consultant or registrar – who specialises in hypertension. But. Only let them discharge you when your BP is reduced and stable. In the meantime, ask for review every 3-6 months – this can be virtual. They can also get you to see a hospital-based dietitian. This may be needed as being overweight or obese is often the major factor contributing to hypertension.
Other hospital consultants. Many smaller hospitals do not have a hypertension clinic. But some heart, diabetes or kidney consultants also specialise in this area and may take referrals. Please ask your GP to recommend one.

Summary

We have described 10 blood pressure facts. If you do all of the above, you will lower your blood pressure and get better care. And this may help to prevent its complications, like heart failure, strokes and CKD.

Other resources

CKDEx has more information: what is blood pressure.

Last Reviewed on 3 May 2024