How do I measure my own blood pressure?
Use only a recommended brand of blood pressure monitor
The QHA provides a number of recommended home blood pressure monitoring devices, models and cuff sizes. We supply monitors at discounted rates to support QHA’s education and research goals in the fight against high blood pressure.
Consistency and reliable results
For consistency and reliability of results, blood pressure should be measured:
on the same arm (every time);
at approximately the same time in the day, and
under the same conditions each time i.e. relaxed, still, quiet and completely undistracted.
Important: Only use fully charged batteries to power your blood pressure monitor. Underpowered batteries will not provide accurate pressure or pulse rate readings.
Make sure you have the correct cuff size
Cuff size is extremely important to get a proper reading! An upper-arm blood pressure monitor will come with a cuff that wraps around your arm. If you use a cuff that is the wrong size for you, your blood pressure reading will not be correct.
Measure around your upper arm at the midpoint between your shoulder and elbow, and choose your correct cuff size:
Small 18 - 22 cm
Medium 22 - 32 cm
Large 32 -45 cm
Most home blood pressure monitors will come with a medium-sized cuff. You may have to order a different-sized cuff separately if you need a smaller or larger cuff.
When to take a blood pressure reading
Start by taking your BP upon rising in the morning and after emptying your bladder or just before you go to bed at night.
To help ensure a reliable reading, avoid eating, smoking, exercising for at least 30 minutes before taking a measurement. Try to take a reading at the same time every day.
If your treating doctor or GP also wants you to take your BP during the day - another BP reading can be taken 2-3 hours after your morning medication.
It's a good idea to start off by taking 2 or 3 BP readings daily for 1-2 weeks. After that, it is recommended to monitor your BP for 7 days prior to seeing your treating doctor or GP.
If your BP medication is altered by your doctor it is wise to monitor your BP readings, for 7 days, to reflect on the effects of any medicine change.
How often should I monitor my blood pressure?
Not seeing the doctor for a while? It is recommended that hypertensive patients should monitor their BP, with 7 day readings, every 6 - 8 weeks.
Sitting, lying down or standing to take a reading
Every doctor has a preference for taking a blood pressure measurement. They may recommend sitting, lying down or standing. Follow their advice.
If sitting in a chair make sure your feet flat on the floor and place your arm on a table so that the arm cuff will be the same level as your heart. You can also lie flat on your bed with one pillow supporting or stand up to take a reading. If standing, stand for 2 minutes before taking a measurement.
How do I apply the arm cuff?
You can use either the left or right arm - just be consistent in BP monitoring.
Remove any tight-fitting or thick clothing from your upper arm. Do not roll up your sleeve if it is too tight.
Put your arm through the cuff loop. The bottom of the cuff should be 1-2 cm above the elbow.
Apply the cuff to your upper arm so that the coloured marker is centred on the middle of your inner arm and points towards your middle finger. The air tube should run down your forearm and be in line with the middle finger.
Pull the cuff so that the top and bottom edges are tightened evenly around your arm. Close the fabric/velcro fastener firmly. You should be able to fit your index finger between the cuff and your arm. Make sure there are no kinks in the air tubing.
Five minutes of quiet time
Sit or lie quietly for 5 minutes with no talking, moving about, distractions such as TV or extreme temperatures.
Sit with your feet flat on the floor, legs uncrossed, back and arm supported in a relaxed position.
How to take a measurement
Press the START/STOP button. The arm cuff will start to inflate, automatically determining your ideal inflation level, and the monitor will start the measurement. Remain still and do not talk during the measurement.
When measurement is complete, the monitor displays your blood pressure and pulse rate. The monitor will automatically deflate the cuff.
Wait 2 – 3 minutes before taking another blood pressure measurement and always record your readings for your treating doctor.
Use the same monitor to measure your blood pressure – some monitors store the results of measurements in memory.
Notes on Safety
Do not use a blood pressure monitor on infants or persons who cannot express their consent.
Do not use a blood pressure monitor for any purpose other than measuring blood pressure.
Do not use a mobile/cellular phone near the unit. This may result in incorrect operation of the unit.
QHA legal disclaimer:
The “How do I measure my own blood pressure?” educational guide is not a substitute for health and medical advice. It is recommended that intended blood pressure monitor users seek the advice of a qualified health professional or their treating doctor regarding a health or medical condition.
Queensland's Hypertension Units - Greenslopes Private Hospital and Princess Alexandra Hospital.
The combined GPH/PAH Hypertension Units have an international reputation for its meticulous approach to the diagnosis and treatment of hypertensive conditions, and for the clinical research into hypertension causes and management.
Patients referred to the Hypertension Units undergo a thorough assessment in order to confirm the diagnosis of hypertension and to determine its severity, and a detailed search is undertaken in order to look for specifically treatable or curable forms.
The GPH Unit received wide acclaim for its discovery that one potentially curable variety of hypertension which affects the adrenal glands ("primary aldosteronism") is at least ten times more common than was previously suspected.
The GPH/PAH Units use state-of-the-art approaches to both non-drug and drug treatment of hypertension, involving the services of the QHA, and the use of the best available antihypertensive medications.
“Thank you very much for your help, care and advice. I am very impressed with the care I have received at the Hypertension Unit and you should be very proud of the team you have”. (PH from Maleny)
“Just wanted to say a great big thanks for all you’ve done. Now four months after my adrenal operation I am on no medication for high blood pressure. I feel great and I am very grateful to you and the staff for the wonderful care they gave me during my stay in hospital.” (RB from Purga)
Help in Managing
How does QHA provide “education in
self-management” for high blood pressure?
A key role of the QHA is to offer services that do not interfere with anti-hypertensive treatment or advice provided by the patient’s own doctor or medical special. In fact, the services QHA offers may complement and assist your doctor.
When and why should I consult my doctor?
If you decide to restrict your salt intake to help in lowering your blood pressure, read this:
A woman who is already pregnant should not reduce her salt intake without the full knowledge and agreement of her doctor.
Patients who take lithium or diuretics ("fluid tablets or "water pills"), or any medication for high blood pressure, should always consult their doctor.
Will my prescribed medications be affected if I reduce salt?
How can QHA help me?
QHA offers a range of services to hypertensive patients,
The sale and maintenance and accuracy check of
inexpensive “aneroid” or fully automated home blood
pressure machines (regular or large-sized cuffs are
available), and instructions by trained nurses in their
Advice on improved lifestyle modifications including
exercise and relaxation programs, self-measurement of
BP, weight reduction, cholesterol-lowering diets and
alcohol and smoking control;
Advice on the avoidance of dietary salt, including low-salt
recipes and foods, important in prevention and control
of high blood pressure; and
Educational materials and Blog articles containing
information on hypertension and lifestyle management.
Tell me how QHA educate and raise awareness for high blood pressure?
The QHA also provides information to patients, health
professionals and the general public through:
QHA's bi-monthly newsletter, The BP Monitor that incorporates
Salt Skip News, an informative read packed with information
on blood pressure, salt reduction, latest research and news,
recipes and lifestlyle tips.
Appearance at health promotional events; and
Regular meetings, held every second month at Greenslopes
Private Hospital in Brisbane, with a different educational topic
covered at each meeting.
All I Need To Know About My Blood Pressure
Notes in question and answer format prepared by QHA Founder, Emeritus Professor Richard Gordon of the University of Queensland, for the Queensland Hypertension Association Inc.
Hypertension or High Blood Pressure
Q: What is blood pressure and what should the blood pressure be normally?
A: The function of the blood is to carry oxygen (picked up in the lungs) and nutrients (picked up in the gut and liver) to all the tissues of the body, and also to carry away waste products for excretion by the kidneys and lungs. In order to move around the body (circulate), the blood must be pushed by the heart's pumping action. This generates a head of pressure in the vessels between the heart and the tissues (large arteries, small arteries and arterioles) which is much lower in the smallest vessels (capillaries) of the tissues themselves, and in the veins which return the blood (aided by a system of valves, and by the pumping action of muscle contraction) to the heart.
The pressure in the arteries (arterial blood pressure) is usually measured in the upper arm artery (brachial artery) and expressed in units called millimetres of mercury (mmHg). It varies with each heart-beat, from a high point (systolic) to a low point (diastolic), and also from beat to beat, being low during horizontal rest (especially sleep) and in high with exercise, emotion or strain.
Arterial Blood Pressure (mmHg) (picture of graph would need to draw or find an internet picture)
Brief rises to very high levels (for example 200/120 mmHg) during strenuous exertion occur frequently without ill-effects, and can be contrasted with very low levels (for example 60/40 mmHg) during sleep. Levels of 100-140/60-90 are those usually measured in normal persons during a visit to the doctor. From the point of view of your heart and arteries, the best blood pressure is the lowest you can tolerate without fainting. Because blood pressure varies so much normally, it is best not to try to define an upper limit of normal bases on a single reading.
Q: How is the blood pressure measured?
A: The diastolic pressure can only be measured accurately by placing a needle of hollow tube directly into an artery such as the brachial (arm) or the radial (wrist) artery. Much has been learnt about blood pressure by doing this, but it is obviously not suitable for routine use. In 1905 a Russian named Korotkoff described a method for measuring blood pressure which combined a stethoscope developed recently in the U.S. with an occlusive cuff recently developed in Italy by Riva Rocci and in England by Hill and Barnard. By feeling the artery at the front of the elbow and placing the stethoscope over it, and inflating the rubber bag inside the cuff wrapped around the upper arm above systolic pressure before releasing the pressure slowly, thudding sounds can be heard over the artery as the blood comes through (systolic pressure), but then disappear at approximately diastolic pressure. The pressure in the bag can be measured using a mercury manometer or an aneuroid gauge. The whole device is called a sphygmomanometer. Especially modified sphygmomanometers which make it easy for a person to take his or her own blood pressure are now widely available, but not all of them are reliable. The Queensland Hypertension Association Inc. (QHA) selects reliable models, after testing, and will supply them, at reasonable cost. You need to be instructed in the correct use of the instrument by the QHA, or your regular doctor. Since variability is the biggest problem in assessing the blood pressure level, obtaining frequent levels at home under conditions of everyday living can be extremely helpful. This is a good example of how patient and doctor can work together in a team approach.
Q: Does it matter if blood pressure is high?
A: Yes it does. Because the higher the blood pressure the harder the heart has to work, and like a weight-lifter's muscles the heart muscle gets bigger and bigger. Eventually it outstrips its own blood supply and the shortage of oxygen leads to chest pain (angina), heart attack (myocardial infarction) or heart failure, with breathlessness on exertion and ankle swelling. In our society most of us develop hardening of the arteries (atheroma), usually from middle age but sometimes earlier. This affects the main artery (aorta) and also the arteries to the heart (coronary arteries), to the kidneys (renal arteries) and to the brain (cerebral arteries). Various factors predispose to atheroma formation, and hence to heart attack – the so-called "risk factors". The most important is high blood pressure itself (hypertension), and other important ones which interact with blood pressure levels are fats in the blood (serum cholesterol), cigarette smoking and obesity (over-weight). Atheroma in the brain arteries predisposes to stroke, and if the blood pressure is high at the time this can take the form of a cerebral haemorrhage, often with extensive brain damage.
Apart from atheroma in the arteries to the kidneys reducing their blood supply, high blood pressure is detrimental to the kidneys in another way. We are born with approximately one million functioning units (nephrons) in each kidney, and these gradually "wear out" until in a normal 70 year old, about half remain. The higher the blood pressure the faster they wear out, so that one of the effects of longstanding hypertension is kidney failure. Good control of hypertension will prevent this accelerated fall-out of nephrons.
Q: How will I know if my blood pressure is high?
A: You probably won't. That is unless you have regular checks by your doctor. This is because high blood pressure usually gives rise to no symptoms. If it does, they usually take the form of headaches or a full or fuzzy feeling in the head. Many hypertensive patients get their first symptoms (a symptom is something noticed or complained of) and signs (a sign is something the doctor can notice or look for) only when complications develop such as heart failure or kidney failure. Don't let this happen to you!
Q: How often should I have my blood pressure checked?
A: This depends to some extent on whether it is already known to be normal or raised, and on your age, and on the presence of other "risk factors" which would make the appearance of high blood pressure particularly dangerous. But, in general, annual checks after the age of 30 years are sufficient, but should be more frequent if the level is not perfectly normal. If a raised level is recorded, then frequent checks will be necessary for a time to establish the level, and to monitor changes with time and with treatment.
Q: Can blood pressure be too low?
A: Yes it can, and this is known as hypotension. It is usually worse on standing (postural hypotension) and can vary from simply a nuisance to a totally incapacitating. It is much less common than high blood pressure, and is usually more difficult to treat. It leads to dizziness, especially on first standing, and can produce fainting attacks with falls and injury, when systolic blood pressure drops to less than 80mmHg. Sometimes it has a cause for which there is specific treatment (for example, adrenal cortical insufficiency or Addison's Disease), but more often treatment must be less specific, such as raising the head of the bed to minimize postural drops in blood pressure when rising, administration of sodium chloride tablets (ideally in a slow-release preparation to reduce gastrointestinal side effects) to expand the blood volume and effective pressure applied to the legs.
Q: What causes high blood pressure?
A: There are many different causes. Some of them, like chronic kidney disease (for example, chronic glomerulonephritis or chronic pyelonephritis), cannot be cured. Others, such as tumours of the adrenal gland or narrowing of the arteries to the kidneys, can be cured, usually by surgery (to remove the adrenal) or special radiological procedures (to dilate a narrowed kidney artery). There are also certain causes which respond well to specific medications which work by reversing the effects of the cause itself. Curable and specifically treatable forms are probably detectable in 10-15% of patients with hypertension, and easily recognised incurable causes in another 10%. This leaves around 75% of patients in whom the cause of the high blood pressure is not obvious. The disease these patients suffer from is usually called "essential hypertension", or "primary hypertension", meaning not secondary to a known cause. There are probably many different causes of "essential hypertension" and this category is shrinking thanks to hypertension research and to improved tests aimed at recognising a treatable cause. High blood pressure itself is not a disease, but a sign of an underlying malfunction, just as fever is a sign of underlying disease.
It is known that essential hypertension occurs with a greater frequency in populations which have a high intake of common salt (sodium chloride) in the diet. So salt is, directly or indirectly, a cause of high blood pressure.
Q: What are the tests which my doctor is likely to ask for?
A: The urine is usually tested for sugar, blood and protein and also looked under the microscope for the presence of blood cells, debris and bacteria. It can also be cultured, looking for infection. The level of blood of the waste products which the kidney excretes can also be measured as a crude test of kidney function. Approximately two thirds of the functioning units (nephrons) in the kidney will be lost before these levels increase above normal. At the same time the level of various "electrolytes" (such as sodium and potassium), urate (raised in gout), glucose and fats (cholesterol and triglycerides) in the blood are usually measured. A renal isotope scan or renal artery duplex ultrasound scan (RADU) may be requested, looking for evidence suggesting a narrowed artery to the kidney. The thickness of the muscular wall of the heart can be assessed by an electrocardiogram (ECG) or, better still, an echocardiogram (ultrasound), and these will also tell something of the function of the heart. A chest X-ray may be requested to look at heart size. Various hormones which can cause high blood pressure if produced in excessive amounts in the body (for example, by an endocrine tumor secreting hormones) can be measured in blood or urine.
Q: Can high blood pressure be treated?
A: If a treatable cause is found, specific treatment is undertaken, and even severe hypertension can sometimes be cured by removal of the cause. Whether or not a cause is found, high blood pressure can virtually always be lowered to normal with non-drug and drug treatment. The risk of suffering a stroke or of kidney damage then falls immediately.
Q: What treatments are available? Will I have to take drugs?
A: There are a number of non-drug treatments available, and these can be tried first, before drugs, provided the blood pressure is not dangerously high. This is well worthwhile because there is a tendency for blood pressure to fall with repeated measurement on no treatment (as you get used to the doctor), or while taking inert tablets (placebo treatment). If you started drug treatment immediately, this good effect would be attributed to the drug or drugs.
The non-drug treatments which have been shown to be effective are:
Reduction of the amount of salt in the diet.
Weight reduction if you are overweight.
Achievement of physical fitness
Regular relaxation (say, twice daily for 20 minutes).
Reduction of alcohol intake if you have more than four to six drinks per day.
In addition, if you are a smoker and have high blood pressure, you must stop smoking, as smoking and high blood pressure are such a potent combination in leading to disease of the heart and of the arteries generally that you court disaster to continue.
Even if your high blood pressure is severe enough to require drug treatment, the non-drug measures mentioned above can have worthwhile effects and reduce the dosage of drugs which you have to take. This reduces the likelihood of side-effects.
Q: How does smoking hurt me? What if I smoke only a few cigarettes a day?
A: Smoking hurts in many ways. Apart from the obvious and serious increase in incidence of lung cancer and in chronic bronchitis, there is an equally serious effect on the arteries. Severe atheroma is common among smokers, especially women at the time of the menopause, and results in blockages of arteries to the heart, legs, gut, kidneys and brain. Smokers lose limbs, a fact which is often forgotten. Once this disease develops, it is too late – it can't be reversed. As well, a smoker who has a heart attack has a much higher probability of experiencing sudden death than a non-smoker. This occurs because of a disturbance of heart rhythm, and happens even when the heart attack is small and otherwise minor. This bad effect disappears immediately you give up smoking.
Your best chance of achieving long-term success giving up smoking is to stop suddenly and completely – go "cold turkey". Thousands have done it, and lived to tell the tale. The QHA will help you with further advice and guidance, if required.
Q: How can I reduce dietary salt, and how strict must I be?
A: The most effective way to start is by no longer adding salt to your food at the table, and by avoiding really salty foods such as bacon and salted peanuts. This step alone will reduce your daily intake of sodium from about 180 mmol to about 120 mmol. By avoiding salt in the cooking, and avoiding canned foods and salty foods (such as cheese) and condiments, you may get down to 100 mmol/day without buying special foods. If you need to go lower and 1 mmol per kg per day is recommended, you will need to buy special salt-free foods such as bread and butter. The QHA can tell you where these are available. In general, the further you reduce your salt intake, the lower your blood pressure will be. If you are going to reduce your sodium intake below 80 mmol per day, this should be cleared by your doctor. The level of dietary sodium restriction which you have achieved can be monitored by measuring urinary sodium in a 24 hour collection. Most patients can achieve an 80 mmol sodium diet with appropriate advice and grow accustomed to it. With less added salt, the natural tastes and flavours of the food come out. If you feel some foods are too bland, you can use peppers and spices to flavour them. Some excellent cook-books are available, and the QHA can help you with these, also. More and more common foods, such as bread and cheese, are now widely available in low salt form, and wholesalers, supermarkets and stores are now aware of the importance of this.
Q: Can I do harm by reducing my salt intake really low? What about hot weather or sweating?
A: The level of urea and creatinine in your blood are crude kidney function tests mentioned earlier which will almost certainly have been done as part of the exploration for the effects of high blood pressure on target organs, and to exclude chronic kidney disease as a cause of hypertension. In patient with elevated blood levels of urea and creatinine indicating chronic kidney disease the remaining functional units are carrying such a load of waste products that they cannot regulate up or down normally for salt. Very low and very high slat diets are dangerous for them. Therefore discuss it with your doctor before going to extremes of sodium intake if your blood level of urea or creatinine is raised.
In hot climates and in subjects who sweat a lot (for example heavy work), the salt retaining hormone aldosterone is secreted in large amounts and the kidneys hold on to the salt so that it is not lost in the urine. The hormone also acts on the wall of the gut and on the sweat gland so that very little salt is lost in the sweat. This is part of the process of acclimatisation, occurs over a few days, and explains why native populations close to the equator with little access to salt have no problems due to salt deficiency, and in fact enjoy normal blood pressures. Therefore the taking of "salt tablets" is rarely, if ever, necessary.
Q: Should I reduce dietary cholesterol?
A: There is a normal range for cholesterol in the blood, and if your cholesterol level is high normal or raised, it makes sense to reduce it, since high cholesterol is another risk factor, like hypertension, for the development of atheroma and heart attack. Your cholesterol level will almost certainly have been measured. By reducing cholesterol and saturated (animal) fats in your diet, your level of cholesterol can be lowered. Excluding eggs from your diet (egg-yolk is extremely high in cholesterol) is an important step. If it is not lowered enough by diet alone, various drugs which act in conjunction with a low cholesterol diet to lower cholesterol are now available. Hypertensive patients should have fasting levels of cholesterol checked, along with a biochemical screen of kidney function, about once yearly. The QHA can provide you with advice about dietary cholesterol and animal fat.
Q: Is it safe to exercise if I am hypertensive?
A: Yes, but it is best to get advice from your doctor or from the QHA about how much and how quickly. As a general rule, it is always safest to start slowly and work up. Isotonic, aerobic exercises like walking and swimming and water aerobics are best. Walking is an excellent form of exercise which is very safe. Gradually increase the distance traveled, and aim to walk every day (or night) if possible, and a minimum of three times weekly. Jogging should only be undertaken with the blessing of your doctor and after obtaining a well-padded pair of shoes if you are going to jog on firm surfaces such as bitumen. Strenuous games of squash are best avoided unless you are very fit already. Intense isometric exercise such as heavy weights are best avoided because they can transiently cause large elevations of blood pressure.
Achievement of physical fitness is associated with a small but very worthwhile reduction in blood pressure. It will also make you feel better and more alert. You will get through your daily tasks more easily. Because your muscles will work more efficiently, you will achieve more with less effort.
Q: How much alcohol can I have?
A: There is probably considerable variability from one person to another in the amount of alcohol which can be taken without long-term ill-effects. The acute effects of alcohol (euphoria, relaxation going into drowsiness and loss of coordination) are well known. Heavy binge drinking and consistent moderate to heavy drinking can lead to liver damage and heart damage.
Ingestion of more than six average-sized alcoholic drinks per day can lead to sustained hypertension. The actual number of drinks required to produce this effect will vary from person to person. When this effect develops, it includes resistance to the action of drugs used to lower blood pressure. Thus, much larger doses of drugs will be required and they are much more likely to have side effects. Therefore, keep your intake of alcohol down to low levels. If you are a beer drinker, switching to "lite" beer can be helpful.
Q: How can I learn to relax?
A: There are many books describing relaxation techniques which are easy to learn. These must be practised twice daily for about twenty minutes. Books are available from the QHA and also from the Relaxation Centre. A clinical psychologist can teach you an effective technique and produce a personalised tape for you. It doesn't seem to matter which form of relaxation you use, for example, deep muscular relaxation, Yoga or Transcendental Meditation. A very useful reduction in blood pressure occurs while you are relaxing. Blood pressure is also lower in between relaxation sessions. Other beneficial effects will be a calmer disposition and improved ability to cope with emotional stress.
Q: How can I lose weight?
A: Your doctor can advise you here and may refer you to a dietitian if he feels you have a particular problem. The majority of overweight people need to change their eating habits so that the total caloric intake each day is reduced. As long as you are losing weight, it doesn't matter how slowly this is achieved. Just keep it moving in the right direction, and don't give up just because you have a set-back or two, due to breaking away from your diet, and actually gain a little weight. Ask your doctor to set you a realistic goal. If you need to drop below an intake of 1200 calories per day in order to lose weight, it is a good idea to take a multivitamin tablet or capsule daily. In general, it is simple carbohydrates (like sugar, sweet things) and fats (high in calories) which you need to restrict in order to lose weight. "Slimming tablets" work by reducing your appetite, but all are related to amphetamines and have side-effects. In some persons they cause extreme and dangerous elevations in blood pressure even if this was normal to begin with. They are best avoided.
Q: What does drug treatment consist of? Are there side-effects?
A: Drug treatment consists of tablets or capsules taken regularly, one to three times daily. If drugs are not taken regularly, it is very difficult to gauge their effectiveness. Since it is so difficult to remember to take drugs regularly, you may need to devise a system to help you. The QHA can help you to obtain a DOSETT, a Swedish invention which allows you to store a full week's supply of different tablets in up to four doses daily in a plastic box with compartments for each dose. If you are having trouble remembering your tablets or if your tablets are giving you side-effects, please tell your doctor. They won't blame you, and they can help, usually by changing to a different but related preparation.
All antihypertensive tablets have side-effects such as interference with sleep or sexual function, or production of dizziness on standing, in some, but not all people. Thus it is often a matter of trial and error to see which tablets suit you best. The newer tablets which have recently become available have fewer side-effects, but even the latest tablets can have side-effects in some patients, and this is usually unpredictable. Drugs which have their greatest effect on blood pressure in the standing position can lead to giddiness (postural hypotension). In general, any treatment which lowers blood pressure will make the patient feel less energetic, until accustomed to the new level. Don't be afraid to discuss the side-effects with your doctor.
Finally, high blood pressure or hypertension is a very common condition in which a change to a healthier lifestyle can make a very big difference. It provides an opportunity to work with your doctor and take much of the responsibility for your own future.