High Blood Pressure

Blood pressure refers to the force with which your heart pumps blood throughout your body. It varies from person to person. Even for the same individual, blood pressure may vary from time to time when, for instance, when one gets angry versus when one is relaxed.

Blood pressure is expressed as a fraction of two numbers and is measured in mm Hg (millimetres of mercury). The first number is the systolic pressure, i.e. the pressure with which the heart contracts and pumps blood to the rest of the body. The second number is the diastolic pressure, which is registered as the heart relaxes and its chambers open, filling with blood.
In general, blood pressure is classified as shown below:

Classification

Systolic (mm Hg)

Diastolic (mm Hg)

Normal

< 130

< 80

Pre-hypertensive

130-139

80-89

Hypertensive

≥ 140

≥ 90

When a person’s blood pressure is consistently at or greater than 140/90 mm Hg, he is said to have high blood pressure or hypertension.

Hypertension increases one’s risk of cardiovascular disease as the blood vessel walls become irritated by the increased pressure exerted by the blood flowing through. As more and more damage is done to the vessel walls, plaque tends to form, in turn increasing the likelihood of atherosclerosis and coronary heart disease.

In about 5% of hypertensive cases, the cause of elevated blood pressure can be attributed to a specific condition or illness such as kidney disease or a structural abnormality of the aorta. Such cases of secondary hypertension can usually be cured by appropriate medical treatment.

For the majority of hypertensive patients however, no explanation for their high blood pressure can be found. Evidence suggests that this form of hypertension, also known as primary hypertension, is caused by a combination of hereditary and lifestyle-related factors such as excessive salt intake, obesity, and stress.

As with secondary hypertension, primary hypertension can be lowered through medication. Weight reduction, regular exercise, and salt restriction are also essential control measures.