Know your numbers - learn more about what blood pressure really means

Having high or low blood pressure is something that you might not necessarily notice, but it’s important to be aware of the implications of both and get yourself checked. Up to 7 million people in the UK are living with undiagnosed blood pressure issues, and if left untreated, it can lead to further health problems down the line. For this reason, it is important to get your blood pressure checked.

Knowing your numbers - what is considered low blood pressure and what is considered high blood pressure?

Blood pressure is a measure of the force of the blood on the walls of the arteries as the blood flows through them. Blood pressure is measured in millimetres of mercury (mmHg) and is usually recorded with two measurements, these are:

- Systolic pressure - this is the pressure when your heart beats and squeezes blood into your arteries 

- Diastolic pressure - this is the pressure when your heart is resting between beats

For example, if your systolic blood pressure is 120mmHg and your diastolic blood pressure is 80mmHg, your blood pressure is 120 over 80, which is commonly written as 120/80.

Typically, if you have a blood pressure reading of 140/90 or higher, you will be regarded as having high blood pressure. On the other hand, if you have a blood pressure reading of 90/60 or below, you will be regarded as having low blood pressure.

What’s the difference between low and high blood pressure?

Our heart does a great job of pumping blood constantly around in our bodies, helping to deliver essential energy and minerals for us to function. Pressure is needed in order for this to happen, but if there is too much and our blood pressure is too high, then this can damage our arteries and heart.  In contrast, if blood pressure is too low, then this can prevent a healthy flow of blood to the brain and other organs, leading to a feeling of dizziness or even fainting. Low blood pressure is not as concerning as high blood pressure, but it should still be monitored as a precautionary measure.

What lifestyle factors may trigger high blood pressure?

There is not always an obvious cause of high blood pressure, but there are a series of lifestyle choices that you can make to help protect yourself against a potential increase in pressure. 

A lack of physical activity and avoidance of exercise can contribute to high blood pressure and if you are obese or very overweight, this can also be a risk. Eating a diet that is high in salt is not advised for those with blood pressure issues and a high alcohol intake can also have adverse effects. High blood pressure can also be a genetic issue and if your family has a history of it, then it’s wise to keep track of your own pressure level. The older you get, the more likely you are to suffer from high blood pressure, and as a result, individuals over 65 are more at risk.

What actually happens in our body when we have high blood pressure?

Our arteries carry blood to the brain and other vital organs in our body and they also control the flow and speed that blood moves at.  Blood pushes against the walls of the arteries and with this, the muscles of the walls expand and detract in order to deal with the pressure of the blood. If the walls are narrow, then this means that less blood can flow through the arteries and it pushes more against the artery walls. In response, the muscles push back against the blood and this in time makes them grow bigger, creating thicker arteries and restricting blood flow. If arteries burst or become blocked, then they can’t supply oxygen to parts of the body; if the brain is starved of oxygen this can cause a stroke and if the heart has restricted blood flow this can cause a heart attack.

High blood pressure can also lead to your heart becoming enlarged and not being able to pump blood as normal, which can lead to heart failure.

What do high blood pressure medicines actually do?

High blood pressure cannot be cured, so if you begin taking medication, it will be a long-term arrangement. Medication can be prescribed to reduce the volume of blood in the blood vessels, by helping the kidneys to remove salt and water from the body, slow the heart rate so there is not as much pressure on the heart to pump as hard, stop blood vessels tightening, target receptors in the brain that can lower blood pressure and relax the blood vessel walls. 

It is very important to check what is your blood pressure level and, if diagnosed with high blood pressure, to work with your doctor to find a combination of medication that is right for you. It is also important to monitor the progress of your treatment and let your doctor know when you can no longer feel the effects of the medicines. Self-diagnosis and buying medication without a prescription can be very dangerous.

If you have checked your numbers and your blood pressure levels are consistently above 140/90mmHg, you should consider taking blood pressure-lowering medication. As part of our online pharmacy service, we provide a confidential consultation with our dedicated GP, Dr Helen Webberley. She will review your condition, your medical history and prescribe you with a suitable treatment.