Hypertension (or high blood pressure) is a common condition worldwide, and is known to be one of the most important risk factors for strokes and heart attacks. It is considered to affect almost a third of all adults over the age of 18. Its prevalence is thought to be increasing to almost epidemic proportions, especially in developing countries. This could be due to many reasons, including better access to healthcare whereby diagnosis is made (and therefore reporting rate rather than true incidence rate is increased), and the increasing “westernization” of lifestyles.
It is interesting to note that hypertension was not always considered a “bad” condition. Indeed, it was considered by the physicians of the early 20th century to be an important compensatory mechanism for the body to cope with illness, hence the term “Essential hypertension”, which unfortunately is still used today, much to the confusion of medical students. It was only in the late 1970s that the first clinical trials were conducted to see whether or not lowering blood pressure would improve patients’ lives. Not surprisingly, these studies showed a significant reduction in heart attacks and strokes following treatment for high blood pressure.
Hypertension in the long term can affect many organ systems, resulting in their damage (what is referred to as “target organ damage”). The most common effects are left ventricular hypertrophy, which is a concentric thickening of the heart muscle, kidney damage, and effects on the microcirculation of the eye (hypertensive retinopathy). However, the more catastrophic effects of hypertension are heart attacks and strokes. This is paradoxical and has been referred in the past as “the Birmingham paradox” (after the research group that first described it). The paradox is that in hypertensive patients, we have the blood vessels being exposed to high pressure, and one would expect that most of the strokes seen in hypertensive patients would be of a hemorrhagic nature. However, most strokes observed are thrombotic (due to a blood clot). This has been explained by the fact that there is significant platelet activation and endothelial dysfunction in these patients, which can lead to thrombosis rather than hemorrhage.
Headaches and visual disturbances are the common symptoms noticed in patients with high blood pressure. Most patients with hypertension however, do not have any symptoms and are often picked up on routine screening. Occasionally high blood pressure is picked up for the first time when patients present with either a heart attack or a stroke, hence the term, “silent killer”.
Our understanding of hypertension has changed and current guidelines for the management of hypertension suggest not merely trying to bring down blood pressure to a certain cut off level, but, importantly, assessing the overall cardiovascular risk of the patient (i.e. the risk of that particular patient developing a heart attack or stroke within the next 10 years). Along with pharmacological medications, lifestyle modifications are also very important. Dietary changes include reducing salt intake, as chronic increased salt ingestion is associated with a high risk of developing hypertension. In today’s world, we have to be careful, as there is a lot of “hidden” salt in our food. Most processed food (and indeed fast food) has a high salt content, mainly as preservatives, but these can over a long period of time cause hypertension. Reducing alcohol intake, increasing the amount of exercise, and eating what is often referred to as the “Mediterranean diet” can all help reduce blood pressure. The Mediterranean diet is one which is rich in fresh fruits and vegetables and fish.
However, all these life-style changes are limited in the amount of blood pressure reduction they can achieve. The mainstay of hypertension treatment involves tablets, of which there are many different classes. Although there are different subgroups of patients who would benefit from one group of drug over another, in general, most patients can be treated with most drugs. It is often difficult to persuade asymptomatic patients to take tablets that make them feel worse, due to the side effects, in the hope that they might prevent a heart attack or stroke. However, it is essential that patients are counselled with regards to the need for continuing with medications.
Thus we can see that attitudes towards high blood pressure have changed over the last century and indeed over the last few decades. Far from being “essential”, hypertension is now known to be fatal, and its management involves lifestyle changes in addition to pharmacological medications. Many public health initiatives to reduce the amount of salt in our food and provide clear labelling on salt content may go a long way in helping to reduce and prevent the development of hypertension. With better preventive and treatment strategies, it is hoped that in the future, this “silent killer” will not be as fatal as it is now.
Featured image by CDC/Amanda Mills acquired from Public Health Image Library. Public Domain via FreeStockPhotos