Unfortunately, there are often no symptoms of high blood pressure – which is why it is often called the “silent killer”.

You will often find out you suffer from high blood pressure (hypertension) on a routine visit to the doctor, or when going to see the doctor about another complaint (which may be as a direct result of your high blood pressure).

It is possible that you might suffer from headaches, nausea, dizziness or blurred vision, but many people will not even experience these symptoms.

High blood pressure puts your cardiovascular system under enormous strain, which can result in serious health problems, even death. High blood pressure is often responsible for heart attacks, strokes, and aneurysms.

When you suffer from high blood pressure, the capilliaries in your body can be easily damaged because of the pressure, meaning organs such as the eye and kidneys can be easily damaged.

How to tell if you have high blood pressure

There is only one way to be certain. Get it measured.

You can go to your doctor, or get a home blood pressure monitor and measure it yourself. Because of a syndrome called White Coat Syndrome, I personally prefer to measure mine myself.

There are various drugs and medications for high blood pressure treatment, though these can often have undesirable side-effects.

There are also natural ways you can reduce your blood pressure as well, including changing your diet, increasing exercise, giving up smoking and losing weight. In fact, I personally reduced my blood pressure to normal using a combination of these “natural methods”. You should also be aware that changes to your exercise and diet can be responsible for more than just lowering your blood pressure. Being more careful with the food you eat and doing a little more exercise can help reduce factors such as stress, heart disease, cholesterol, arthritis and prevent onset of diabetes.

Don’t risk being the next victim of the silent killer.

Do you have high blood pressure at the doctors yet normal at home?

You may suffer from white coat syndrome.

A true story

I went to my doctor and was told I suffered hypertension. My blood pressure was 140/90. I was told I needed a lot of medical checks – weekly blood pressure readings, blood tests to check for cholesterol, thyroid problems etc, and urine tests, I guess to check for protein (which are normally not present in urine, but can be under extremes of pressure).

For my first weekly blood pressure check, I turned up on time for my appointment only to learn that she had gone off for lunch. Now, I am a patient man (no pun intended), but was not going to wait for her to return. I decided to go to the Pharmacy to get my blood pressure checked.

To my disappointment, my blood pressure was 140/100. The pharmacist asked if I was on medication. I was not, and did not want to be. I went home and did some research on the internet. I learnt about a phenomenon called white coat syndrome which made a lot of sense to me. The mere act of going to a doctor (white coat) made you nervous and increased blood pressure.

Well, the recommendation on the internet was to get a home blood pressure monitor. I bought one which had a cuff that went around the wrist, but found it inaccurate after checking at the pharmacy, so bought one that used an upper arm cuff. After getting it checked for accuracy at my doctors, I started taking my blood pressure at home on a daily basis.

To my amazement, my blood pressure during a typical day ranged from 130/90 to 110/65.

Certainly my blood pressure was not always high, and very rarely as high as it always seemed at the doctors office.

I now had it in my power to change my diet and monitor my blood pressure changes.

Giving up smoking cigars had a dramatic effect on my blood pressure. In addition, increased water intake to 3 litres or more a day, and decreased caffeine to 1 cup of coffee a day (I drank decaffeinated after this first one). Today, my blood pressure averages about 124/78. That’s normal.

Conclusions about white coat syndrome

Certainly my blood pressure at the doctors office was always higher than when measured at home. I have no doubt that white coat syndrome is a very real problem, and one I myself suffer from. I highly recommend you buy a home blood pressure monitor and check your blood pressure at home. Some doctors recommend this as a way of knowing your true blood pressure. Plus you can check what effects your lifestyle have on your blood pressure. This is the only way I have found to find an accurate measure of my blood pressure, while avoiding the elevating effects of white coat syndrome.

There is a suggestion that if you suffer white coat syndrome, it may indicate that your hypertension is linked with stress. Going to see the doctor stresses you and your blood pressure increases. If this is true, then just because white coat syndrome is responsible for your elevated blood pressure, it does not mean you are fine. You should continue checking your blood pressure at home, and also try to reduce stress levels in your daily life. Relaxation and meditation on a daily basis can help with this.

If you found this article about white coat syndrome interesting, you may be interested in learning more about diet changes that can help reduce your blood pressure.

Before we look at how to use a home blood pressure digital monitor, and which ones are the best, let’s first consider what the blood pressure readings will mean. These figures are taken from the National Heart, Lung and Blood Institute.

Digital Home Blood Pressure Monitors v Doctor’s sphygmomanometer

When you get your blood pressure measured at the doctor’s office, he/she will place a cuff around your upper arm, level with your heart.

The cuff is inflated, and then, while the doctor listens on his/her stethoscope placed on your arm just below the cuff, the cuff is slowly deflated. the doctor is listening out for the first signs of a "tapping sound" which signals the point when the cuffs pressure is just less than the pressure of your blood, and blood flows intermittently past the cuff during heart beat. At this point, the doctor notes the pressure on the sphygmomanometer. This is your systolic blood pressure.

The cuff continues to be deflated until the "tapping" sound completely disappears. This is the point where full blood flow has been restored, and represents your diastolic blood pressure.

Measurements taken by your doctor are the most accurate, and most reliable. However, due to a phenomenon called "White Coat Syndrome", some patients find their blood pressure raised by the mere act of visiting the doctor. I suffer from this, and find that my blood pressure is significantly lower (even normal) at home, yet at the doctor’s office, it is always high. Because of White Coat Syndrome, more and more doctors are recommending digital home blood pressure monitors for their patients.

If decide to buy a home monitor, you MUST get it checked at your doctor’s office for accuracy. These meters can be extremely accurate, but you need to check that yours is calibrated properly. All you need to do is to go and get the doctor to check your blood pressure, wait 2 minutes, and then take your blood pressure using your digital meter. The two readings should be very similar (they wont be 100% the same as blood pressure varies). Once accuracy is confirmed, you can confidently take your blood pressure at home.

Types of personal blood pressure monitors

I have seen and used two types of home monitors. One has a cuff that goes around your wrist, while the other has a cuff that goes around your upper arm (at the level of your heart). While I have not done extensive testing, I did find the wrist cuff more temperamental and inaccurate. My own recommendation is that you buy a blood pressure monitor with the arm cuff. They are both similarly priced and can be bought for between $50 – $100.

Precautions when taking your own blood pressure

It is important that your are completely relaxed when you measure your blood pressure. There are also a few other guidelines that you should stick to before taking your reading:

1. Empty your bladder before sitting down to take a reading.
2. Don’t drink coffee for at least an hour before measuring your blood pressure.
3. Don’t smoke for at least 1 hour before.
4. Sit for five minutes with your back supported and your feet flat on the ground before taking your blood pressure. Keep your arm supported on a table at heart height.
5. Do not wear tight fitting clothes on your arm. When you fit the cuff, your rolled up sleeve should not be constricting your arm at all. If in doubt, take off your top.
6. Take two readings two minutes apart, and find the average.

Where to Buy Blood Pressure monitors

With these personal monitors being relatively cheap and yet highly accurate, we recommend you buy one to use at home. This will prevent "White Coat Syndrome" where your blood pressure is elevated just because you visit the doctors. However, when you get your, you must visit your doctor to check its accuracy. 

Our recommended supplier of blood pressure monitors usually have a range of wrist and upper arm cuff monitor.  See our guidelines to choosing a blood pressure monitor, and see what is available online:

Choosing a blood pressure monitor

I used a filter coffee machine to prepare a large cup of coffee, made with decaffeinated ground coffee. The process was exactly the same as my experiment to see if caffeine coffee affected bloood pressure, except for the type of coffee, which in that case was obviously a standard caffeine coffee. In the current experiment, the coffee was decaf.

Here are my results:

Here is the data as a graph showing the effect of de-caffeine coffee on blood pressure:

Before drinking the coffee, my blood pressure was fairly stable at around 125/82. However, at 10:31, around 5 minutes after drinking the decaf coffee, my blood pressure fell to 116/78, and fell even further at 10:36 to 112/75.

For 10:31 to 10:50, my blood pressure was below the starting blood pressure of around 125/82. From 10:58 until the end of my experiment, blood pressure had returned to near the starting level.

It appears from these results that drinking the decaffeinated coffee reduced my blood pressure for a period of around 25 minutes before blood pressure returned to normal.

Now, whether this is due to the decaf coffee itself, or some other factor involved remains to be seen. For example, it may well be that the decaf coffee itself has no effect on blood pressure, and something like the heat in the drink was responsible.

As a follow up experiment, I need to drink an equivalent volume of hot water.

That will be my next experiment.

To prepare for each set of readings, I sat down for 5 minutes before taking the first reading.

The coffee used in this experiment was strong filtered coffee. After taking a few baseline readings, I drank the coffee in one go. The amount was equivalent to 4 small expresso coffees. I then continued to take my blood pressure every few minutes. I then sat as still as possible, taking my blood pressure every three minutes.

Here are my results:

Here is the data as a graph showing the effect of caffeine coffee on blood pressure:

You’ll see that there is an almost immediate increase in systolic pressure, followed by a drop. This then increases again about 10 minutes after drinking the coffee to a maximum measured blood pressure of 138/89 about 23 minutes after the coffee was drunk. The blood pressure then starts dropping again, until normal blood pressure is restored at around 30 minutes after drinking the coffee.

What we see happening is a temporary increase in blood pressure in response to the coffee, which the body then corrects. How caffeine raises blood pressure seems to be unclear, but what is certain in my case is that it did raise my blood pressure, but only for a short period of time.

For those with high blood pressure, it would appear that coffee could be a problem due to the high spike after drinking the coffee. However, since my blood pressure is normal, I wont be switching to decaf.

My next experiment is to see what effect drinking filtered decaffeinated coffee has. Is it the caffeine in the coffee that raised my blood pressure, or something else?  You can see the results of my experiment on the does decaffeinated coffee affect blood pressure page.  The results may surprise you!

To prepare for each set of readings, I got into position, and waited quietly for 5 minutes before taking the first reading.

I then took a minimum of 3 readings for each position, with 3 minutes between each reading. The results I show you below are the average of the readings for each position. I have also included heart rate for the three positions.

Blood pressure when lying down:

Blood Pressure Average: 115/70
Heart Rate: 66

Blood pressure when sitting down:

Blood Pressure Average: 120/79
Heart Rate: 72

Blood pressure when standing :

Blood Pressure Average: 121/78
Heart Rate: 75

As you can see, my blood pressure (and heart rate) was lowest when lying down. This is as expected, since the body is not having to work too hard to pump blood around the body, which is all pretty much in the same horizontal plane.

When the body then sits up, there is an increase in blood pressure and heart rate. Again, this is as I would have expected, since the body is now having to work a little harder to get the blood around the body.

Finally, when standing, there was no noticeable difference in my blood pressure from the sitting position. I had expected to possibly see a slight drop in blood pressure, though no change is not a big surprise. When you stand up, gravity causes blood to naturally wants to pool in your leg veins causing a drop in blood pressure. However, the autonomic nervous system tries to correct this by narrowing your blood vessels (which increases blood pressure) and increasing your heart rate. We did see the increased heart rate. The reason for no apparent drop in blood pressure is probably because the first reading was taken 5 minutes after standing. This would have given the body time to adjust.

Incidentally, I am not a doctor. These experiments are for my own curiosity, and I do not recommend you do the same.

Here are my results:

Here is the chart of this data:

While the graph may not look too impressive, you can see a large jump in blood pressure almost immediately. Before starting to smoke the cigar, the average blood pressure for the three preceding readings was 133/83. The first reading after starting to smoke was 149/92. That’s quite a jump.

The initial increase in blood pressure is spectacularly quick. Not surprising really, as smoke enters our bodies through the thin membranes of the lungs, as well as through the membranes in our mouth. This is why smokers can get a neat instant “hit” when they light up.

Blood pressure is raised for about 20 minutes before it returns back down to a more normal reading (that’s normal for me). When there is a stimulus to increase blood pressure, our bodies are going to try to combat that increase and lower the blood pressure. In this case it took about 20 minutes for my body to do so. Blood pressure then remained fairly constant for the remainder of the experiment.

It would be interesting to see how blood pressure would be affected if I continued to smoke all day (as in a chain smoker), and whether my body could compensate over a long period of time. I wont, however, be doing that experiment ;o)

Look out for new experiments soon. You’ll find them in the left hand menu.

The readings were not taken at specific intervals, and I have made no attempt to show on this graph when I ate food, did exercise, drank coffee, or anything else that might affect blood pressure. The whole point of this experiment was just to see how my blood pressure varied throughout the day.

Here are my results:

Average Blood pressure over the day: 129/82

Here is the chart of this data:

The fluctuations were not as big as I anticipated, but one thing I have noticed is that my blood pressure does tend to reduce as the evening progresses.

We have to be careful to draw any conclusions from this blood pressure data, but clearly, there is some variation during the day.

I will be looking at specific influences in other experiments, and how they affect my blood pressure, so look out for those. They will be listed down the left of this page.