One of my students asked me recently about what yoga can do for people with high blood pressure (or hypertension). I’ll attempt to answer this question here, drawing on some reference books as well as articles published on the Yoga International website.
What exactly is blood pressure? It’s a way of measuring the force that the heart generates to circulate blood around the body. The figure that we hear when a doctor measures our blood pressure (e.g. 130 over 85) refers to the systolic pressure and the diastolic pressure in that order. Systolic pressure is the pressure generated when the heart pushes blood out (essentially how well the heart is doing), and diastolic pressure is the pressure when the heart rests between beats (essentially how well the system is doing).
According to the NHS, ideal systolic pressure is somewhere between 90 and 120, and diastolic pressure is between 60 and 80. High blood pressure is anything over 140 on the top or 90 on the bottom, and anything under 90 on the top and 60 on the bottom is considered low. However, blood pressure varies considerably with age, so a 20-year old with a reading of 120/80 is in less good shape than a 60-year old with the same reading.
Many people with hypertension show no external symptoms and may not even be aware of the condition. As high blood pressure is linked with heart disease, kidney failure and strokes, periodic checks of blood pressure are advised in anyone over the age of 35 (and if you are aware you have had high blood pressure in the past, the charity Blood Pressure UK recommends having it checked at least annually).
The exact causes of high blood pressure or hypertension are not known, but it is more likely to affect people who smoke, drink excessively, fail to take enough exercise or lead very stressful lives. Having said that, there is a definite link between the stress response and our blood pressure: when we experience stress, our blood pressure rises, so one way of lowering this pressure is through learning to lower our feeling of stress.
Our breath is a fundamental tool for learning to reduce our experience of stress. Deep, slow, even breaths bring the body back into its natural balance and help us to calm down, as everyone who has ever helped calm someone else down knows. This is one of the key ways in which yoga can help – during a yoga class we focus on using the full diaphragm to breathe, and over time this trains us to breathe like this outside class too.
Yoga does not just work with the breath. It also influences the brain, through positive thinking and thought control, and the muscles, through relaxation. The guided relaxation at the end of a yoga class has been shown to reduce hypertension significantly, and to ‘reset’ what the body holds to be normal blood pressure at a lower level.
Another benefit that yoga practice offers is exerted on the baroreceptors, which are sensors that detect and control pressure in the cardiovascular system. These are exercised and toned through the practice of yogic inversions (for example the shoulderstand) and are therefore more likely to be kept in working order for longer as we age.
A final consideration is the possibly surprising fact that our blood pressure rises when we speak. Through the practice of yoga, we get used to withdrawing the senses inwards, like a tortoise withdrawing its limbs in towards its shell. For those of us who talk a lot and suffer from high blood pressure, this aspect of yoga is therefore potentially very beneficial too.
Personally, I have noticed that when I am practicing yoga regularly, my heartbeat is much quicker to return to normal after a period of exertion. I love the inverted postures, and perhaps what I really mean by that is that my cardiovascular system loves them, as they provide ample opportunity for this system to relax and recalibrate.
Someone taught me that as we have two ears and one mouth we should listen at least twice as much as we speak, and it is interesting to learn that there may be sound scientific reasons for this advice too!