Blood Pressure: WTF?

Blood pressure is one of the most common observations that doctors, nurses and healthcare workers will take. We put on that cuff, it tightens then loosens and we write down the results. If you’re in hospital this might be several times a day, if you’re in the community it might be every time you visit the GP. Considering we take this reading so often it’s fair to assume we would have an excellent track record monitoring and controlling a patient’s blood pressure. Unfortunately this isn’t always the case. It’s estimated that 6 million Australians over 18 have high blood pressure and approximately two thirds of those people don’t have good control over it.

In this article, which is a companion piece to my video titled, “Blood Pressure: WTF?”, we’ll learn more about blood pressure, why it’s important and how to control it.

WHAT IS BLOOD PRESSURE?

Blood pressure is a very literal name: it’s pressure from the blood! Blood pressure is the force exerted on the walls of our arteries by the blood as it is pumped around the body by the heart. Simple!

HOW DO WE MEASURE BLOOD PRESSURE?

We measure blood pressure using a cuff known as a sphygmomanometer (quite a mouthful, right?). This cuff constricts the artery and we can either then use a stethoscope over the artery to listen for the blood pressure on a manual cuff or an electronic cuff will measure it itself. We measure blood pressure as two numbers known as the systolic and diastolic readings. The first reading, the systolic, is the maximum pressure being exerted on your arteries in that moment as the heart pumps. The second reading, the diastolic, is the minimum pressure being exerted on your arteries in that moment as the heart relaxes. We put these two numbers over each other to look something like this: 120 (systolic)/80 (diastolic). The units we measure blood pressure in are millimetres of mercury (a unit used to measure pressure).

Healthy blood pressure is essential to ensuring that oxygenated blood is easily carried around the body to all the relevant organs and tissues without damage occurring to those vessels in the process. High blood pressure is known as hypertension and low blood pressure is known as hypotension. Blood pressure that is both too high and too low can have serious negative consequences for somebody; finding balance is imperative. Here is a good, general guide for blood pressure readings:

optimal <120/<80

normal 120-129/80-84

high-normal 130-139/85-89

mild hypertension 140-159/90-99

moderate hypertension 160-179/100-109

severe hypertension ≥180/≥110

(Source: Better Health Channel)

(The only addition I would make to this guide is that a blood pressure reading of <90mmhg systolic and <60mmhg diastolic would be considered too low, or hypotensive.).

Blood pressure can be tricky to monitor because it’s dynamic; it’s always changing to meet our body’s needs and so what we see on one reading may not be truly representative of our blood pressure. There are many factors that affect our blood pressure. Some of them are temporary, such as the position we’re sitting in, our breathing pattern, our emotional state or even recent caffeine or exercise. There are also factors that permanently affect our blood pressure and change its baseline level to be too high, including but not limited to poor diet, lack of exercise, smoking, genetics, being overweight, high cholesterol and some mental health issues. Finding out what is causing your hypertension is imperative to understanding how to treat it.

For this reason if you get a reading that is too high or too low it’s important not to just go off one reading as a definitive measure of your blood pressure. Go back to see the doctor or nurse a few more times to get an overall picture, or buy a cheap monitor and do some readings at home.

WHY DOES THIS MATTER?

Having optimal blood pressure is incredibly important because both hypertension and hypotension can lead to devastating consequences. Hypertension contributes to the majority of cardiovascular disease in Australia and is disturbingly common. Hypertension is so insidious because it usually produces no symptoms and so we aren’t aware of it until it causes something more serious. Hypertension can lead to heart disease, including heart attack, stroke, kidney disease, eye disease and more.

Hypertension damages the body in several ways. Firstly it can lead to blockages in the arteries through an increased build up in plaque. If an artery is blocked then it is more difficult for blood to travel where it needs to, for instance the brain or the heart itself. A lack of oxygenated blood is known as ischaemia and can lead to stroke or heart attack. Hypertension can also damage and rupture blood vessels and arteries themselves through prolonged pressure. This causes bleeds in the body that can lead to stroke, kidney damage, damage of blood vessels in the eyes and more.

Low blood pressure, or hypotension, can also have serious consequences. Usually hypotension is caused by an external event, such as blood loss or dehydration, however it can have an underlying pathological reason as well. Some people can maintain low blood pressure without consequence however for others it can cause dizziness, fainting, nausea or even lead to shock. If you have persistent low blood pressure it is important to discuss this with your doctor and monitor this regularly.

HOW DO I CONTROL MY BLOOD PRESSURE?

Thankfully blood pressure is something that can be controlled through both lifestyle and medication. If you have abnormal blood pressure it is imperative to act on this quickly, especially in relation to hypertension. The longer blood pressure is high the more potentially irreversible damage it is doing to your body.

Before medication is ever introduced to monitor blood pressure lifestyle changes should always be trialled first. We live in an age of poly-pharmacy, especially for older people, however blood pressure is something that can be positively impacted by our lifestyle (as negative lifestyle choices often contribute to hypertension in the first place!). Try to introduce at least 30 minutes of activity at least 5 days a week. The activity needs to be moderate in intensity; cardio is recommended over weight-training for blood pressure control (such as a brisk walk or cycling). Meditation can also offer wonderful benefits for blood pressure control if stress or mental health issues are contributing to hypertension.

A proper diet is fundamental to blood pressure control. We live in an age of takeaway and processed food that is high in fat, salt and sugar and it’s all so easy to get our hands on (not to mention it tastes so damn good!). Unfortunately these kinds of food have devastating effects on our cardiovascular health. If you have high blood pressure it’s important to have a diet that firstly adheres to correct portion sizes and is rich in vegetables, fruit and whole grains. Reduce high-fat and high-sugar foods as much as possible, or have them as an occasional treat but not everyday. Try to avoid added-salt at all costs! Salt increases water absorption in the body and leads to higher blood pressure. If you’re lost about where to start with your diet then a wonderful place to start is discussing the DASH diet with your doctor, which stands for Dietary Approaches to Stop Hypertension.  

If a change in lifestyle factors hasn’t worked or your blood pressure is clearly caused by a genetic predisposition to hypertension then medication might be your best option. A person is often started on a low dose of medication, known as antihypertensives, which may need to be gradually increased. There are a lot of different agents that can treat high blood pressure and sometimes a combination of a few drugs is needed. It’s important that you continue to regularly monitor your blood pressure and review your medication with your doctor or nurse for as long as you need medication. Too often there are patients who have been on medication for months or years without a repeat blood pressure review only to discover that the antihypertensive is no longer providing benefit.

Blood pressure is arguably one of the most fundamentally important vital signs and indicators of cardiovascular health. Now that you know a little more about Blood Pressure I encourage you to research it for yourself but most importantly #CHECKYOURPRESSURE ! It’s such an easy thing to do and can prevent some serious health consequences down the line.

Have a peruse through some of these great resources below and remember, ‘There is no healthcare without self-care!’

 

RESOURCES / REFERENCES:

Heart Foundation of Australia, 'Blood Pressure.'

Better Health Channel, 'Blood Pressure.'

Better Health Channel, 'Hypertension.'

Mayo Clinic, 'DASH Diet / Health Eating and Nutrition.'

Mayo Clinic, 'Risk of High Blood Pressure.'

Mayo Clinic, 'Risk of Low Blood Pressure.'

NOTE: This blog was made in part from the resources above, clinical nursing resources that are unavailable online and relevant clinical experience.