Understand your own blood pressure — better than your Doctor
Take charge of your own risk factors
When I ever I visit the USA I’m always amazed by the medical conversations I randomly hear in public places. Its not uncommon to sit in a restaurant, hotel lobby or bar and catch random medical words wafting around—then of course, as a Doctor, its very hard not to listen in to more details. “I used to be on Ramipril 2.5mg but my blood pressure is creeping up so I made appointment to see my Cardiologist and discuss increasing my dose” or “What’s your cholesterol? I think I’m going to change to Lipitor 40mg” or “I’m going to meet my Gastroenterologist to discuss if I need a check-up Colonoscopy”(!)—the [over]awareness of medical conditions and treatments is amazing and very different to the UK. There are of course positives and negatives to this psyche. Some of this is as a result of the greater freedom for the pharmaceutical industry to advertise directly into the public subconscious and some due to a better awareness of the ‘value’ of healthcare (and indeed more expensive treatments down the line).
What is true is that patients who are more actively engaged in their own care and informed are more successful at taking charge and improving their own health. Your GP’s attention is stretched by the numerous patients they are simultaneously looking after and they are getting ever more busy. By understanding your own risk factors better than your own GP you will be able to better tailor your own healthcare and help guide your doctor to optimise your health.
Blood pressure — the basics
To appreciate the importance of blood pressure and the reasons to maintain a healthy blood pressure, we need to first understand what those numbers mean to you. Those two numbers are phenomenally important to your future. In fact, it no exaggeration to say they predict your present and future health.
Your heart is simply a pump. It pumps blood around the body to supply all your organs through ‘pipes’ which make up the vascular system. Together the heart and these blood vessels make up the cardiovascular system. The higher-pressure vessels (‘pipes’) which deliver blood away from the heart are called arteries and the lower pressure pipes which deliver blood back are called veins.
Blood pressure is simply a measure of the pressure in the arteries. Healthy arteries are thin walled, elastic and flexible. They stretch and recoil in response to the wave of blood ejected with each heart beat to efficiently transport this blood downstream.
When you have your blood pressure taken there are two quoted numbers — the top numbers is called the systolic and the bottom number the diastolic. Systole is the medical word for when the heart contracts causing an increase in the pressure within the arteries — the maximum pressure equals the systolic pressure (the higher number). When the heart relaxes (diastole) the pressure drops and the minimum pressure in the arteries at this point is the diastolic pressure (the lower number).
Why is blood pressure important?
Blood pressure is a direct indicator of the health of your cardiovascular system. We have already discussed that healthy arteries are thin walled, elastic and flexible and the same is true of the heart. A healthy cardiovascular system transports blood in a smooth and efficient manor to supply all the organs of the body. The heart muscle itself, brain and kidneys are particularly demanding and require an efficient blood supply. If this supply is slowed or compromised (or the delivery pressure too high) these organs and the associated fine, delicate arteries at the end of the system, become damaged easily and much of this damage is irreversible. These organs have a lot in reserve and so the damage is not noticeable at first (which is why you don’t notice anything or feel unwell) until a certain threshold of damage is passed. For this reason it is essential to protect and prevent damage far before this threshold is reached when the result can be catastrophic such as a heart attack, stroke or kidney failure. Remember — prevention is better than treatment and the process starts as a young adult.
What is a healthy blood pressure?
Less than 140/90 (anything consistently above is high)
But for simplicity — forget the bottom number (diastolic) and focus on the more important top number (systolic). Your blood pressure should be less than 140 (120–130mmHg is ideal).
< 140 mmHg
Your blood pressure is constantly changing to meet the demands of your body. If you stand up suddenly you need a transient increase in pressure to get the blood to the brain, for example. If you have a fright or are stressed then your blood pressure will increase (this is a primitive reflex designed to ‘fight’ or ‘flight’ in the face of an attack). If you are relaxed and sitting still you need less blood pressure and so it is lower.
Despite this, your blood pressure should be consistently less than 140/90 on average. The ideal blood pressure is around 120/80. This is irrespective of your age and high blood pressure is not an acceptable consequence of getting older.
If you can take your blood pressure readings at home you should not simply focus on your best readings — don’t fool yourself — if some readings are consistently over this number you have high blood pressure. If the readings are high when you visit your GP then this should not always be dismissed as ‘white coat syndrome’ — you may still have high blood pressure (on average) and a 24-hour blood pressure investigation can be arranged by your doctor.
Do not accept even mild levels of high blood pressure as this will be causing silent and progressive damage. The higher your blood pressure the higher your risk. For every 20 unit (mmHg) increase in systolic blood pressure over 120 you will double your future chances of a heart attack and stroke. By the same account if you reduce your blood pressure by 20 units you half your chances — phenomenal! Why not start to make yourself disease proof.
High blood pressure — a dangerous (but silent) viscous cycle
Lets now consider the damaging viscous cycle of high blood pressure. We now know that a healthy cardiovascular system is made up of thin walled arteries which are elastic, flexible and transport (‘waft’) blood in a smooth and efficient wave to the far reaches of the body without the need for high pressures in the system. An unhealthy cardiovascular system is exactly the opposite. The heart and arteries become thick walled and stiff —this can progress to ‘furring’ of the inner lining (atheroma) . The arteries lose the ability to relax (which would normally allow the vessels to become larger), become constricted and resistant to the flow of blood. Higher levels of blood pressure are required to force blood through these vessels and supply the organs. This puts extra strain on the heart muscle and artery walls which continue to get thicker and stiffer through progressive damage.
Remember that even mild levels of high blood pressure can kick start this process. If the blood pressure is uncontrolled then a vicious cycle of higher pressures and progressive damage is established. This process progresses silently (and painlessly) until the damage is irreversible and the end result is a cardiovascular ‘event’. This is not fortune telling — the statistics are clear and well established. Uncontrolled high blood pressure will eventually lead to heart attacks, strokes (both blood clots or bleeds into the brain), aneurysms (ballooning and weakening of the walls of the arteries), visual damage or kidney damage. Even one of the most common causes of dementia in the elderly is slow but progressive brain damage as a result of years of high blood pressure.
The most important reversible cause of high blood pressure in the modern world is an unhealthy diet and lifestyle.
Blood pressure indicates the health of your cardiovascular system
Your arteries do get stiffer with aging (like the rest of your body!) and this is related to a trend of increased blood pressure with age but you should not except higher blood pressure as inevitable. You should regard blood pressure as an indicator or gauge of your general health. High blood pressure for the majority means that something is wrong and needs to change. An unhealthy diet and lifestyle is the most common trigger for the viscous cycle of blood pressure and this is in your control. If the gauge suggests you are becoming unhealthy then it is within your control to do something about it. Medications are not always the right answer and if you address the issue early enough (before irreversible damage) then you can avoid the need for more aggressive treatments later on.
We want to be clear here — as Cardiologists we are absolutely in favour of appropriate medical treatments in patients with established high blood pressure but what we are saying is that many people can avoid or delay that step. Medications are damage control but are not always treating the underlying cause. Even in individuals with established damage (such as a heart attack patients) the power of diet and lifestyle above and beyond medical treatments can make a massive difference in preventing further damage and improved repair and recovery.
Hopefully with the insight provided above you are now motivated to find out how you can control your own blood pressure through the phenomenal power of diet and lifestyle. Whatever your age — if your blood pressure is high, do something about it and you will live longer and healthier!
The follow up article to this post will be simple, modern, evidence-based dietary and lifestyle strategies which can make a significant difference to your blood pressure today — watch this space.