High blood pressure (also known as hypertension)
is one of the most common medical conditions
and its prevalence continues to rise.
According to a recent study, the number
of people affected by high blood pressure
has almost doubled over the past 40 years,
and there are about 1.13 billion people living
with the condition worldwide.
As hypertension generally develops over
many years with no distinctive warning
signs or symptoms, many people don’t even
realize they have high blood pressure.
Left untreated, it can lead to life-threatening
conditions such as heart failure,
stroke or kidney disease. The World
Health Organization estimates that
hypertension causes 7.5 million deaths
a year, which equates to about 12.8%
of all deaths worldwide.
Many of these deaths could be prevented,
as high blood pressure can be detected
with a simple test and can often be controlled
with a healthier lifestyle and appropriate medication.
This eBook has been
developed by Idorsia Pharmaceuticals Ltd as a resource
to help the understanding of hypertension. It provides
a useful summary of current information about the
condition, the diagnosis procedure and available
treatments. It also outlines the strategies people
with hypertension can use to manage their
condition as effectively as possible.
The book is intended for the use of a general
Complications of untreated hypertension
Blood pressure is not a steady number,
but can be affected by what time of
day it is, eating and exercise habits,
stress levels and other factors.
These short-time fluctuations are
normally nothing to worry about,
but if blood pressure remains too
high for a long period of time,
problems may arise. Hypertension –
high blood pressure – can “overwork”
the heart and cause damage to blood
vessels, which can harm other
important organs over time.
It is important to understand how
our body controls our blood pressure,
risk factors for hypertension and the
different types of hypertension.
Blood delivers nutrients and oxygen to all parts of the body, pushed through a vast network of large and small blood vessels when the heart contracts.
By widening or narrowing, the vessels adjust to the blood pressure and keep the blood flowing at a healthy rate.
The more blood the heart pumps and the narrower the vessels, the higher the blood pressure.
There are several factors that contribute to systolic blood pressure: the measure of the pressure inside your blood vessels when the heart contracts.
One of them is the changing structure of the walls of our blood vessels as we grow older. They thicken and become stiffer and less flexible. This increases resistance to blood flow; the heart has to pump harder to force the blood through, leading to increasing blood pressure.
Take the example of 130/80 (130 over 80), which is the upper threshold for normal blood pressure, according to the new guidelines issued by the American Heart Association in 2017.
The top number – 130 millimeters of mercury (mm Hg), the unit used to measure blood pressure – is the systolic blood pressure. It indicates the amount of pressure the blood is exerting against the artery walls during heartbeats.
The bottom number – 80 mm Hg – stands for the diastolic blood pressure, which indicates how much pressure the blood is exerting against the artery walls between beats, when the heart is resting.
In this context, it is worth mentioning that blood pressure and heart rate (the number of times the heart beats per minute) are two separate measurements and indicators of health. They do not necessarily increase at the same rate.
Blood pressure consistently lower than 90/60 mm Hg is known as hypotension.
Some people have naturally low blood pressure, which doesn’t cause any symptoms and usually doesn’t require treatment.
However, if blood pressure is too low, the person might feel dizzy and lightheaded.
Any sudden drops in blood pressure require immediate medical attention – they can be life-threatening. Causes include severe blood loss, dehydration and severe allergic reactions.
What medical treatments are available for hypertension?
While making changes towards a healthier lifestyle
(as described in the next section) often have a
significant impact on lowering blood pressure,
they might not be enough on their own and need
to be supported by medical treatment. The
category of drugs prescribed will depend
on the blood pressure category and medical
history of the patient.
Blood pressure medications are often more
effective in combination than as a single drug.
However, finding the most effective
combination of drugs while keeping side
effects to a minimum can be a challenge.
Avoiding unwanted interactions between
different medications is therefore an
important consideration for the prescribing healthcare professional.
Diuretics target the kidneys to help the body to eliminate sodium and water, which reduces blood volume.
Alpha blockers keep the hormone norepinephrine (noradrenaline) from tightening the muscles in the walls of smaller blood vessels, which improves blood flow and lowers blood pressure.
Beta blockers work by blocking the effects of epinephrine, a hormone also known as adrenaline. This leads to the heart beating more slowly and with less force and to improved blood flow, which reduces blood pressure.
ACE (Angiotensin-converting enzyme) inhibitors block the formation of angiotensin II, a substance that narrows blood vessels, which, in turn, lowers blood pressure. People with chronic kidney disease may benefit from having an ACE inhibitor as one of their medications.
ARBs (Angiotensin II receptor blockers) block the action – rather than the formation – of angiotensin II. Both ACEs and ARBs are often part of the treatment for people with chronic kidney disease.
Calcium channel blockers reduce electrical conduction within the heart by blocking the entry of calcium into the muscle cells. This decreases the force of contraction of the muscle cells and dilates arteries, thus reducing blood pressure.
Systolic and diastolic pressure
What are the different stages of hypertension?
When a person has elevated blood pressure,
their blood pressure is higher than normal,
but is not in the hypertension range yet.
Medical treatment and, importantly, lifestyle
changes can prevent blood pressure from rising
further, and it is important to have frequent
blood pressure checks to monitor development.
In stage 1 hypertension, systolic pressure
ranges from 130 to 139 mm Hg, or diastolic
pressure ranges from 80 to 89 mm Hg.
For the more severe stage 2 hypertension,
systolic pressure is 140 mm Hg or higher,
or diastolic pressure is 90 mm Hg or higher.
A systolic pressure of 180 mm Hg or higher,
or a diastolic pressure of 120 mm Hg or higher,
is referred to as a hypertensive crisis.
It can be caused by a range of factors,
such as having a stroke, heart attack, kidney
failure or interaction between medications. This
dangerous spike in blood pressure can damage blood
vessels and organs and requires immediate medical attention.
Symptoms of a hypertensive crisis may include severe
chest pain and headache, blurred vision, nausea, anxiety
and shortness of breath. The affected person might also be unresponsive or have seizures.
If someone’s high blood pressure can’t be lowered,
despite treatment with a combination of three
anti-hypertensive drugs of different categories
(including a diuretic), they may have resistant hypertension.
The diagnosis of true resistant hypertension can be challenging, as the so-called white coat effect must be ruled out first.
For many people, their blood pressure is higher when it is taken in a medical setting (by a doctor or nurse in their traditional ‘white coats’), compared to when it is taken at home.
By having patients wear an automatic blood pressure recorder for 24 hours and/or check their blood pressure several times a day, a better account of fluctuations can be recorded and the white-coat effect reduced.
For a correct diagnosis of resistant hypertension, a number of conditions that can cause apparent resistance need to be eliminated. Factors like inappropriate medication dosage and noncompliant patient behavior need to be taken into consideration as well.
How common is resistant hypertension and who gets it ?
Estimations of how many patients with high blood pressure
have true resistant hypertension range from 2%, all the
way to 10%, which reflect the difficulties in diagnosis.
Compared to “regular” hypertension, patients with
resistant hypertension are more likely to be older
(above 75 years of age), overweight and to have a
medical history of diabetes, kidney and heart disease,
stroke, and/or sleep apnoea. Chronic kidney disease and
diabetes in particular, make these patients more
vulnerable and increase the complexity of finding
the right treatment combination.
How is resistant hypertension treated?
Generally, the approach for resistant hypertension
is to add a fourth antihypertensive medication to
the three drugs the patient is already taking. The
fourth drug often has a different mechanism of action,
(the way it works in the body), compared to the other
three medications. Yet these drugs often have their own
limitations and can be associated with side effects that
force the patient to stop taking them.
Therefore, new treatment options for resistant hypertension
are needed, especially for patients in whom other, traditional
forms of antihypertensive drugs are ineffective. Examples of
new mechanisms of action are aldosterone and endothelin receptor
antagonism, both of which have the potential to normalize blood
pressure and improve the function of kidneys and blood vessels.
Practical guidance on managing hypertension
While effective medical treatment can be the key to lowering blood pressure, especially in severe and resistant hypertension, the role of a healthy lifestyle cannot be overstated.
The lifestyle changes described in this section can not only help to lower blood pressure and keep it down, but also to avoid, delay or reduce the need for medical treatment.
If you find you need support beyond your own social circle, you might consider joining a hypertension support group that provides both emotional guidance and practical tips on coping with the condition.
As weight increases, blood pressure often increases as well. Reaching and maintaining a healthy weight is therefore one of the most effective measures for reducing blood pressure and keeping it in check.
Regular physical activity — at least 30 minutes, several times a week — can bring blood pressure down to safer levels, or help to avoid developing hypertension altogether if the numbers are only slightly high (elevated hypertension).
Types of exercise that are well-suited to lowering blood pressure include walking and hiking, jogging, cycling, swimming and dancing. Weight training can also be beneficial.
Anyone with a long-term medical condition should speak to their doctor before starting a new exercise program, to check if they should be aware of any additional considerations.
Whatever the individual exercise routine looks like, it is important to be consistent and stick to it in order to keep blood pressure down.
Although sexual activity is unlikely to pose an actual health risk for people with hypertension, high blood pressure can affect the quality of their sex life.
Over time, high blood pressure damages the lining of blood vessels and causes them to stiffen and narrow, which limits blood flow.
For some men, this decreased blood flow makes it difficult to achieve and maintain erections, (which is medically known as erectile dysfunction). The drugs used to treat hypertension can have similar effects, depending on their mechanism of action.
High blood pressure can also reduce sexual desire and increase anxiety and fatigue in both men and women, which can take a toll on relationships and emotional wellbeing.
By discussing any concerns with a doctor and seeking additional professional help if necessary, people with high blood pressure can address many of these problems. This might include switching to medications that may have fewer side effects.
The so-called DASH (Dietary Approaches to Stop Hypertension) eating plan is supported by the US National Institutes of Health and has been shown to be beneficial for people with and without hypertension. The eating plan is rich in whole grains, fruits, vegetables and low-fat dairy products, and is low in saturated fat, cholesterol, salt and added sugar. It includes the following elements:
fruits and vegetables
low-fat dairy products
unsalted beans and lentils
herbs and spices
small quantities of unsalted nuts and seeds, vegetable oils and lean red meet
Changing established eating habits is not easy, but some simple tricks can help:
Keep a food diary. Writing down what you eat, even for just a week, can shed surprising light on your true eating habits. Monitor what you eat, how much, when and why.
Be smart and educate yourself before you shop or go to a restaurant
Be creative in your kitchen - use herbs or spices to add flavor to your food, or try a new (DASH-friendly) recipe.
Reducing salt (sodium) intake can make a positive difference to blood pressure. The DASH eating plan recommends a maximum of 2300 milligrams of sodium a day. In addition to reducing the intake of “regular” table salt, it is important to check the labels – and sodium levels – of prepared and processed foods.
Sodium occurs in a number of substances added to processed foods, such as glutamate and baking soda. Generally, unprocessed and whole foods are better choices for people on a low-salt diet. Fruits and vegetables in particular are important components of the DASH eating plan - they are low in sodium, but high in potassium and can therefore improve the potassium to sodium ratio, which helps to lower blood pressure.
The beneficial effect of small amounts of alcohol is debatable when it comes to lowering blood pressure – and drinking more than that might not only raise blood pressure, but also make blood pressure medications less effective.
It is therefore recommended to keep to a limit of no more than one drink a day for women, or two drinks a day for men. One drink equals roughly 14 grams of pure alcohol – which is contained in a regular beer or small glass of wine, for example.
The nicotine in cigarettes raises blood pressure and heart rate immediately during smoking. In the longer term, tobacco can damage the lining of blood vessels, causing them to narrow and harden, which increases blood pressure and puts additional strain on the heart.
Stress is an important contributor to high blood pressure. While it is almost impossible to eliminate all of life’s stressors (be they related to work, family, money or health), there are a range of techniques to help manage them effectively
Take a break from the stressor. It is not easy to give yourself permission to step away from that big work task (or from that annoying person at the Christmas party, for that matter). But allowing yourself to take a breather can provide a fresh perspective and make you feel less overwhelmed.
Exercise. A quick walk or run can have an immediate positive effect that can last for several hours, even and especially on a stressful day.
Smile and laugh. Humor or just a friendly face can help to relieve tension and lower stress levels.
Be mindful. Meditation, yoga and other relaxation techniques have been shown to help some people to relax and focus, physically and mentally. Mindfulness can help to develop new perspectives and release emotions that may have contributed to the feeling of stress.
Talk about your feelings. Call a friend, meet for a walk with the neighbor or have lunch with a family member. Sharing your worries with a person you trust often alleviates stress. However, it’s important that the person you talk to is not one of your stressors.
This resource has been developed by Idorsia Pharmaceuticals in order to provide an environment to deliver a better understanding of resistant hypertension and to pool information regarding the disease, the diagnosis procedure, available treatments and the impact it could have on the life of someone diagnosed with resistant hypertension. The resource is for use by a general audience.
The information in this resource is not intended as a substitute for advice/treatment by a physician, whose instructions should always be followed. Neither does the information provided constitute an alternative to advice from a doctor or a pharmacist and should not be used on its own to produce a diagnosis or to commence or cease a particular treatment.
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