Hypertension (high blood pressure) is not a 'disease' per se; it is believed to be a significant risk factor in other diseases, including heart attack, heart failure, stroke and kidney disease. Often called 'the silent killer', the UK medical authorities reckon that 25 per cent of us 'suffer from' hypertension and that it causes over a third of all deaths in people under 65.
How do you get high blood pressure? For most, there is no definite cause, although it appears to be related to diet and lifestyle. This is called 'essential hypertension'.
However, some hypertension has a known cause, including preeclampsia, congenital heart defects, or problems with the kidneys or adrenal glands. This is called 'secondary hypertension', and accounts for 10 per cent of cases. Other causes of secondary hypertension are prescribed drugs such as cyclosporin, oral contraceptives, hydrocortisone, non-steroidal anti-inflammatory drugs (NSAIDs) and tricyclic antidepressants.
A major risk factor for essential hypertension is age. Blood pressure tends to gradually rise the older we get. Doctors used to think this was normal and used a rule of thumb that 100 plus a person's age was an acceptable upper limit for blood pressure. So, a systolic pressure of 160 mmHg was acceptable for a 60-year-old. However, this is now considered outdated, and all of us are encouraged to reduce our systolic levels to 120 mmHg, whatever our age. Nevertheless, this recommendation may be tied to the vast number of antihypertensive drugs on the market, and is not universally accepted by doctors. 'All that these new guidelines essentially accomplish is to convert 45 million healthy Americans into new patients - by creating fear', says Dr Paul J. Rosch, clinical professor of medicine at New York Medical College.