Hypertension and cardiovascular disease
There are at least 970 million people worldwide who have elevated blood pressure (hypertension).
In the developed world, about 330 million people have hypertension, as do around 640 million in the developing world. The World Health Organization rates hypertension as one of the most important causes of premature death worldwide and the problem is growing.81 In 2025 it is estimated there will be 1.56 billion adults living with high blood pressure.
What counts as hypertension?
High blood pressure is defined as a systolic blood pressure at or above 140 mmHg and/or a diastolic blood pressure at or above 90 mmHg. Systolic blood pressure is the maximum pressure in the arteries when the heart contracts. Diastolic blood pressure is the minimum pressure in the arteries between the heart’s contractions.
How hypertension impacts on your heart and blood vessels
Hypertension is a risk factor for coronary heart disease and the single most important risk factor for stroke. It causes about 50% of ischaemic strokes and increases the risk of hemorrhagic stroke.
Hypertension stresses your body’s blood vessels, causing them to clog or weaken. Hypertension can lead to atherosclerosis and narrowing of the blood vessels making them more likely to block from blood clots or bits of fatty material breaking off from the lining of the blood vessel wall. Damage to the arteries can also create weak places that rupture easily or thin spots that balloon out the artery wall resulting in an aneuvrism.
Elevated blood pressure in people less than 50 years old is associated with an increased cardiovascular risk. As you get older, your systolic blood pressure becomes a more important predictor of the risk of cardiovascular disease.
Although increasing blood pressure is part of aging, a healthy low salt diet, physical activity and maintaining a healthy weight can reduce the risk of this happening.
Dietary salt is a significant factor in raising blood pressure in people with hypertension and in some people with normal blood pressure. If you are already overweight then a high intake of salt increases your risk of cardiovascular disease.
Types of hypertension
The amount of blood pumped by the heart and the size and condition of the arteries determines your blood pressure. However, many other factors can affect blood pressure including the condition of your kidneys and levels of various hormones in the body.
Some people experience essential hypertension, which has no identifiable cause. If you are diagnosed with this its origins may be genetic, or due to your lifestyle including diet, weight and physical inactivity. Secondary hypertension is caused by another condition such as problems with your kidneys, certain medicines and some other medical problems.