I know this term often refers to submarines, and in particular the nuclear-powered variety because they can remain underwater and undetected for months at a time. I’ve always been fascinated by submarines, and that is why I, like many others I guess, was drawn to the BBC’s Vigil that was shown recently.
Surprisingly for the BBC this was full of daft plot twists and took theatrical license to the extreme. I certainly wouldn’t have known that officers don’t wear white shirts on submarines, but I didn’t need to be an expert to realize that the space on board resembled a shopping mall in some places.
What did get me going however was when the on-board surgeon announced from a fully kitted two-bed sick bay that the sub didn’t carry atropine, not having it was essential to the plot, but laughable because this is a common emergency drug you would expect to find anywhere. It didn’t exactly have me shouting at the screen, but I could feel myself getting a bit worked up if you know that feeling.
Getting worked up about something, annoyed or agitated are all ways that our blood pressure can change. Going for a run, a swim or a brisk walk can all do the same thing. It is perfectly natural for our blood pressure to change throughout the day depending on what we are doing.
High blood pressure is sometimes referred to as the silent killer, because it creeps up slowly and quietly and often before you realize it the harm is done. So what do we mean when we talk about high blood pressure, how do we spot it, and is there anything we can do about it?
When we measure blood pressure we are generally talking about how hard the heart has to work to pump blood around our body. I often used to ask people to imagine heating system with a pump pushing water around a network of pipes feeding radiators and picking up heat from a boiler. If everything is working well all the radiators will be nice and hot, and the system will tick over quietly. If the pipes get full of sludge, the pump has to work much harder, and even then the radiators won’t feel as hot.
The analogy works very well once you start to think about it; the pump obviously is our heart, the pipes our vascular system made up of arteries and veins, and as for the radiators you can think of them as all the important organs in the body that need oxygenated blood.
If our blood vessels fur up inside then it makes it harder for blood to flow, pressure goes up, the heart is under some strain as it works harder, and chances are that important organs might not get oxygen rich blood in the quantity they really need it.
It used to be quite an art to measure someone’s blood pressure, these days it is very easy with an automatic blood pressure monitor. You can buy these for a very modest price from very well-known on-line stores.
Depending on the type you either wrap it around your wrist nice and tightly, or wrap a measuring cuff around your upper arm, press a button and wait for the result. The machine inflates the cuff and then slowly releases the pressure and as it does so it starts to record your blood pressure as two numbers. Most devices also provide you with a measure of your heart rate at the same time.
Suppose you end up with two numbers like this 120 and 80, what does all this mean? Well of course this being medicine we have to put up with a bit of Latin, the two readings actually refer to the normal or the resting pressure (in our central heating analogy when the pump is off) and that is known as the diastolic pressure, 80 in my example.
The other number is the pressure when our heart contracts and pushes blood out (in the heating analogy the pump is on) we call that the systolic pressure. As I said earlier, you’d expect pressure to go up and down a bit during the day, in the same way your heating pump switches on and off to maintain a steady temperature.
So if your blood pressure slowly starts to creep up the chances are you won’t really notice. You will on the other hand if it gets to a point where you start feeling breathless or you hear ringing in your ears. Too high and that can spell very bad news, just like a heating system that gets over pressurised, pipes and joints might leak – burst even.
Sadly, that happens with us and a few well-known weak points tend to fail time and time again; the delicate blood vessels in our brains as an example. When that happens we call it a stroke, in medical speak we call it a cerebral vascular accident (CVA) as a catch all for that type of internal bleeding, and in the majority of cases blood pressure plays a part.
So how do we keep ourselves healthy when it comes to blood pressure? I am a great believer in knowing what you are dealing with and so I recommend the use of an automatic blood pressure monitor. That way you can keep an eye on things. Some regular mild exercise is definitely on the prescription; so many studies have shown how this helps keep blood pressure in the good zone.
If you still smoke, then I’m afraid you are not helping yourself one bit. Whatever you may think, and indeed whatever your current blood pressure, there is absolutely no doubt whatsoever that smoking stores up problems sooner or later. So, at the very least think about cutting down. An awful lot gets written about what we should and shouldn’t eat, and that even seems to change week to week.
However, one thing is for sure and that is we want to try and stop our blood vessels getting clogged up, and certain types of fat seem to do that very well. I’ve never been a fan of telling people what to eat or not, but I think sensible advice we can all manage to follow it just to make sure our diets are mixed and balanced, so fish and chips and a pint every night is not a good idea, but mixed in with other types of food not necessarily deep fried I don’t see any harm whatsoever.
If you do have high blood pressure and you haven’t spoken to your doctor about this then make an appointment. There are several types of drugs that work really well in reducing blood pressure. It’s important to say that what might work well for one person might not be the solution for you, so don’t be tempted to go to the pharmacy and buy what your friend might have been prescribed. Once the correct drug has been found for you it is a simple case of sticking with it on a daily basis and it will help keep your blood pressure in the safe zone.
Some people have said to me they follow a great diet, take some exercise, don’t smoke but still notice their blood pressure seems to creep up. Well, the aging process is very probably the reason and that’s because as we get older our blood vessels loose some of the elasticity they used to have – they get a bit harder, so instead of relaxing a bit to accommodate a surge in blood flow, they stay hard and a bit narrower, and that pushes blood pressure up. In these sorts of cases we sometimes suggest something to thin the blood just a little, it puts less strain on the heart to push blood around the system if it is a bit thinner. Your doctor can easily test to see if you would benefit from this type of treatment.
Anyway, back to that submarine programme, I have to say I was enthralled. I’m still amazed to think that those enormous, I have to call them boats, things can remain underwater for so long. I don’t know how I would manage, but I take my hat off to those who do.
Dr Marcus Stephan
My views are entirely personal and do not reflect the view or position of any organisation. You should always consult your own medical practitioner regarding any concerns that you may have. Never stop taking any prescribed medication without first checking with your doctor.