An introduction to blood pressure
The term ‘blood pressure’ is one many of us have heard in doctor’s appointments and pharmacy visits over the years, but if you don’t understand what it is, it can be hard to understand what to do about your own blood pressure – or indeed whether anything needs to be done at all. Keep reading to learn more about this important aspect of your overall health and what constitutes ‘normal’ blood pressure.
What is blood pressure?
Put simply, blood pressure describes the amount of effort your heart has to use in order to pump blood around your body. If you have very high blood pressure, your heart is working extra hard to move your blood. On the other hand, if you have low blood pressure, your heart isn’t having to exert itself so much. While it might sound as though a lower blood pressure is best, having too low a blood pressure can cause problems, too. In reality, a blood pressure that sits somewhere in the middle is best.
Blood pressure monitors measure your blood pressure to give two readings: your systolic blood pressure (the top number) and your diastolic blood pressure (the bottom number). Both of these are important readings to take note of in order to fully understand what’s going on with your own blood pressure.
What is systolic blood pressure?
Systole is the term used to refer to the periods of time in which your heart contracts. Not all of the heart contracts at the same time, so systole is split into atrial systole and ventricular systole, named after the different chambers of the heart. However, you’ll only get one reading, which is the pressure created when your ventricles contract and force the blood out of your heart.
What is diastolic blood pressure?
In contrast, diastole refers to the time when your heart relaxes and so the blood pressure is significantly lower. To help remember which is systole and which is diastole, it might be helpful to think of your heart dilating after a contraction. Therefore, diastole = dilation.
When your heart dilates, it’s no longer forcing blood out into your body. In fact, this is when blood re-enters your heart at the other end of the cycle. So, your heart contracts in systole, forcing blood out of the ventricles and into your body. This blood travels around your body, pushed by more contractions of the heart, and then re-enters the heart at a moment of diastole.
What is a normal blood pressure range?
Everyone is different, and what’s healthy for one person might not be healthy for the next. For this reason, blood pressure is categorised in ranges. For example, an ideal blood pressure is considered to be anything between 90/60mmHg and 120/80mmHg, with the first number being systolic blood pressure, and the second being diastolic.
In comparison, low blood pressure is anything that’s below 90/60mmHg. High blood pressure is anything over 140/90mmHg. If you are over 40 and have never been diagnosed with high blood pressure you are eligible for a free NHS blood pressure check at your local pharmacy. If you are taking your blood pressure at home, we recommend doing it at least three times over several days to get an average reading. This can help you to identify any outliers (e.g. an overly high reading due to having just exercised or feeling stressed) and give you a better idea of what your blood pressure really looks like.
On top of that, it’s important to discuss your blood pressure readings with a doctor or pharmacist who can help you to understand what high and low blood pressure mean. If you have high or low blood pressure, it puts you at a greater risk for certain conditions or symptoms, but there are things you can do to either raise or lower your blood pressure to a more ideal level. Whatever the case, speaking to a pharmacist about your blood pressure can help you to feel more confident in managing your health and well-being.