Why is high blood pressure a cardiovascular risk factor?
Normal arteries are elastic and when the heart beats blood into them, they and accomodate the extra pressure. If arteries are harder than they should be – less elastic – or narrower than normal, the heart must beat much more strongly to pump the blood round. Eventually, the heart muscle grows bigger to try to deal with the extra loading, but big swollen heart muscle (hypertrophy) is not that efficient, and after a while, the heart starts to fail. The other factor is that if the arteries are hardened and narrowed, that would include the coronary arteries – the arteries that supply the heart muscle itself. If these arteries are progressively narrowing, there can come a time when they hardly allow any blood through, and the muscle they’re meant to supply starts getting starved of oxygen – particularly with increased physical effort. This is called angina. If those coronary arteries are very narrow, they can also become completely blocked – that’s a heart attack. Lastly, if there’s any wea
