One of the most dangerous aspects of hypertension (high blood pressure) is that you may not know that you have it. Nearly one-third of people who have hypertension don’t know it. High blood pressure is just one of the risk factors for developing heart disease increasing the odds of a heart attack or stroke. But what constitutes high blood pressure? Why do so many people get it? And what can they do to help themselves?
Nurse reading a patient’s blood pressure. Photo credit: James Gathany/Centers for Disease Control and Prevention (CDC) (Image Number: 7882)
The latest guidelines from the National Institute for Health and Clinical Excellence (NICE) define high blood pressure as sustained clinic readings of above 140/90 mmHg, or 135/85 if you are checking it in the more relaxing surroundings of your home. The lower (diastolic) figure indicates the pressure in the arteries when the heart rests between beats, while the upper (systolic) figure is the peak reached with each beat of the heart (felt as the pulse).
The higher the pressure, the greater the likelihood of damage to the delicate lining of the arteries, which in turn causes thickening of the walls and restricts blood flow, increasing the risk of stroke and heart attack — a danger further compounded by other factors such as smoking, diabetes and high cholesterol levels.
Everyone over the age of 35 should know their blood pressure and have it checked annually if it is borderline. An abnormal reading in the surgery should be backed up by lots more taken using either a portable machine that the person wears for a minimum of 24 hours (ambulatory blood pressure monitor) or, more commonly, a DIY machine to take twice daily readings over a week while sitting comfortably at home.
No single identifiable cause is found in the vast majority of people with high blood pressure and it is thought to be owing to a combination of age, genes and dietary and lifestyle factors. However, it is important to do a few basic blood and urine tests to exclude underlying causes such as kidney disease and to check for accompanying hazards such as raised sugar or cholesterol levels.
Once the problem has been picked up, the next step is to work out what to do about it. Useful self-help measures include cutting out salt (during cooking and at the table), avoiding caffeine, increasing intake of fresh fruit and vegetables, losing any excess weight, taking more exercise, drinking sensibly and taking steps to deal with any stress.
For otherwise healthy people with mildly raised readings (160/100 or less) this may be all that is required. But most people with high blood pressure end up taking pills; a third need one medicine, another third will require two and the remaining third will need three different drugs for optimal control. And treatment is invariably lifelong.
I am afraid that pills are often just the start of it. If accompanying investigations turn up other issues, such as high cholesterol levels, then you are likely to be offered treatment for these too (such as statins), and so the slippery slide from person to patient begins.
While there is currently some controversy about whether doctors have become overly zealous when prescribing preventative treatment in otherwise healthy people — particularly surrounding statins and low-dose aspirin — there is general consensus on the importance of treating high blood pressure. High blood pressure is dangerous. As well as increasing the odds of stroke and early heart attack, poorly controlled blood pressure is linked to kidney failure, dementia, loss of sight from damage to the retina and erection difficulties in men.
There are no reliable outward signs of high blood pressure and the only way to pick it up is to have yours regularly checked. I am a great believer in self-monitoring and think everyone should consider buying their own blood pressure monitor once they reach middle age, but don’t overdo it. Take readings twice a day for a week, ignore the first day and average the rest. If it is well into the normal range then put the machine away for a couple of years. If it is borderline, then re-test annually and if it is raised make an appointment to see your GP or practice nurse.