If you're indulging in too much election coverage, consider meditation, yoga or breathing exercises to help lower your blood pressure
Opinion: If watching the news in the run up to the election makes your blood boil, breathe deeply, and try to calm your beating heart. We all need to keep blood pressure in check, high blood pressure being the starting point for many potentially lethal events including atrial fibrillation, stroke, heart attacks, heart failure, kidney disease and so on. Despite 120 years of medical interventions, blood pressure remains one of the most challenging conditions to manage.
This is worrying because at least 10 percent of New Zealanders have high blood pressure. But how do you know if you have it, and if you have it, should you start taking drugs to lower it, and if you do, will they really reduce your chances of having a heart attack or stroke, etc?
The answers to these questions are more complicated than most of us might think. Blood pressure is the physical force of the blood on the wall of the vessel, driven by the heart and the resistance to flow created by the arteries. A normal level of pressure is the optimal force to drive blood to tissues to drop off oxygen and nutrients and to return it to the heart for its re-oxygenation in the lungs.
Our circulatory system is a temperamental thing – blood pressure increases during exercise, when we’re stressed, during sex and even when we go to the loo. We also have blood pressure surges as an involuntary ‘fight or flight’ response, which occurs without conscious thought in response to a challenging situation – a tiger on the savannah in the early days, perhaps now a party’s tax policy in 2023 or the All Blacks losing a game of rugby.
In an age of personalised medicine, we need a complete picture of a patients’ risk factors to decide if they should be treated and how aggressively and not make assumptions based on synthetic pressure thresholds assumed to be appropriate for everyone
Coordinated by the autonomic/sympathetic nervous system this causes huge rises in blood pressure and adrenaline to flow. This sympathetic nervous system comprises bundles of nerves that connect our brain to the heart and every vessel in our body, to prepare us for extreme physical activity. From an evolutionary standpoint this was useful, crucial even, helping us escape from predators. Today sympathetic nerves can become overactivated by stress and anxiety, and conditions such as depression and dementia, and cardiovascular disease is so often associated with these conditions.
When that high blood pressure is sustained above an internationally agreed threshold it’s called hypertension – 140/90 mmHg. The problem is this level may pose no threat for a person that has no other risk factors (eg smoking, obesity, family history, age) and there may be no need to treat it. One needs to assess as many risk factors as possible and if these do exist then lowering blood pressure to 110/75 would be ideal, although this is rarely achieved.
In an age of personalised medicine, we need a complete picture of a patients’ risk factors to decide if they should be treated and how aggressively and not make assumptions based on synthetic pressure thresholds assumed to be appropriate for everyone.
High blood pressure damages the lining of the blood vessels over time, which causes them to stiffen, and affects the vessels’ ability to widen to allow blood to flow. This leads to increased resistance and a further rise in blood pressure.
The domino effect goes on. Inelastic blood vessels put more pressure on the heart which itself stiffens and in doing so it loses its unique ability to dilate and fill, compromising its ability to pump, which can lead to heart failure.
This makes exercise difficult because the heart can’t pump enough blood around the body, which starves the exercising muscle of oxygen. Not being able to exercise compromises every aspect of our physiological (and psychological) selves, including our heart.
But how do you know if you have high blood pressure? This is tricky – blood pressure is a moving target. It has a diurnal rhythm, and is affected by your state of mind, increasing when anxious/stressed and falling when relaxed. Measuring it is an inexact science – just seeing your GP or nurse can automatically increase it in some people (‘white coat hypertension’). A single measurement of blood pressure at one moment in time is of questionable validity.
Measuring your blood pressure at home may be more accurate, which can be done by buying a blood pressure cuff from a pharmacy and keeping a diary noting daily blood pressure, heart rate and state of mind.
Drugs will reduce blood pressure, but what is a safe target pressure level? This will depend on any co-morbidities and risk factors. Then there is the question of which drugs you should take. This is decided empirically yet we know one size does not fit all. In the non-too-distant future, I would hope epidemiological evidence or DNA screening or both would be used to better guide blood-pressure-lowering medication in the future.
But to complicate matters further, strokes and heart attacks also occur during sudden surges in blood pressure (often triggered by stress) and we don’t yet know for sure if prescribed drugs prevent these surges, because blood pressure is rarely measured at this time.
Most readers will know about lifestyle changes that will help: quit smoking if you smoke, reduce salt and sugar in your diet, eat more fruit and vegetables, reduce weight if overweight, and exercise. Every drop counts: just 5 mmHg pressure drop significantly reduces the risk of a cardiovascular event.
Maybe avoid indulging in too much election coverage, and consider meditation, yoga or breathing exercises – something as simple as deep, slow breathing really can help lower blood pressure (10-15 mmHg) and lift our mood.