In some cases, the underlying cause can be found. If you have a narrow renal artery, for example, this reduces blood supply to the kidney. The kidney thinks this means that the blood pressure is too low, and it releases hormones designed to raise the blood pressure - to a level high enough blast the blood supply past the narrowing. If you open up the renal artery surgically, the blood supply is restored at normal pressure, the kidney stops releasing extra hormones, and the blood pressure normalizes.

In around five per cent of cases of high blood pressure, a cause like this is found. In the other ninety five per cent, no cause is found. At which point something very strange happens. Instead of calling this ‘a raised blood pressure where no cause can be found,' the medical profession turned, once again, to the ancient dead languages in order to create a disease. This disease is called Essential Hypertension. This actually means ‘a raised blood pressure where no cause can be found.' But you have to admit that it sounds rather more impressive.

More importantly, perhaps, a process occurred whereby essential hypertension turned from a measurement, into a disease, rather than the body's natural reaction to some underlying problem. And once it became a disease, a whole series of drugs were developed in order to treat it. Some reduce the blood volume, some relax the blood vessels, some block production of hormones produced by the kidneys to raised blood pressure, others stop the heart pumping so hard.

They come by names such as thiazide diuretics, beta-blockers, alpha-blockers, angiotensin converting enzyme inhibitors, angiotensinogen II inhibitors etc. etc. After statins, these are the most prescribed type of medications in the world, and hundreds of millions of people take them each and every day.