High blood pressure or hypertension


Hypertension simply means high blood pressure. It is very common with over a billion cases worldwide. Up to 25% of people have hypertension and many are unaware of it because it produces no symptoms and causes no problems for many years. It is commoner in some ethnic groups, in men, in those with western lifestyles and is more frequent as we age.


High blood pressure is important because left untreated it can lead to heart attacks and strokes. It can cause aortic aneurisms, an enlargement of the main blood vessel which can burst, and it has been linked to specific dementias. Untreated patients go on to develop kidney and heart failure. Properly treated however these risks dramatically fall so it is important we all check our blood pressure even if we are well.


The NHS has many problems but it does excel in screening. GPs provide a valuable service in checking blood pressure, but blood pressure goes up and down in normal life. Exercise puts it up as does stress but as long as your blood pressure is OK at rest it is safe – NASA measured blood pressures of 300 / 200 in astronauts at launch but all were known to be super fit and live to a ripe old age. Your GP therefore has to be careful because many high readings are what we call white coat syndrome. This has been a major issue for anaesthetists because a patient’s blood pressure is often raised in the anaesthetic room due to anxiety, and this led to £870m of NHS operations being cancelled and the operating theatres being left idle each year. Now anaesthetists do NOT take blood pressure before anaesthesia but rely on the reading from the GP.


The issues of getting a reliable reading and avoiding false positives are overcome by self measurement. I recommend my patients over say 40 buy a battery operated blood pressure machine. Omron is a reliable model available from amazon and Boots (other sources are available!!). Buy the cheapest you can find as more expensive models have unnecessary add ons. Take your blood pressure no more than twice a week at different times. Record on your phone or in a notebook:


The high reading called the systolic

The low reading called the diastolic

The pulse.


You will also see the mean reading but this is calculated from the other readings and can be ignored. You need to record WHAT you are doing eg watching TV, lying in bed, just back from the gym. From this we can determine your ‘normal’ blood pressure and discuss if treatment is needed. Even if you have blood pressure and are on drugs, this is worth doing as many people find their reading lower than at the GPs, allowing their drugs to be reduced.


If you have blood pressure your doctor will probably check to see if there are any causes such as kidney disease or diabetes. Obstructive sleep apnoea (OSA) is important and I have a separate blog on this.  Some drugs may be implicated but in a lifetime of medicine I haven’t diagnosed a cause in any patient because if there had been a cause the patient would have been aware of it…… Most patients have what is called essential hypertension, essential just being doctor speak for unknown. It is usually not true because most patients with hypertension are suffering as a result of western living – smoking, obesity, lack of exercise, high fat high salt diets and excess alcohol.


Prevention and management rely on changing this lifestyle, which again I have covered in other blogs. Eat and live more healthily. And if you are in the minority of people with hypertension despite living well all your life, be reassured that your blood pressure is still better than it would otherwise have been.


Many people will need drugs to control their blood pressure. My patients are naturally upset to be told I have diagnosed hypertension but I point out it is good news in so far as by identifying the problem and starting drug treatment we are reducing their risk. Undiagnosed they would have been more likely to come to harm.


There is a wide range of drugs. All of them are very safe with side effects in only a small proportion of patients and if an individual has issues with one drug we can swop to another. They will need to be continued indefinitely with regular blood pressure measurements and blood tests for kidney function every year or so. The increased risk of heart issues means statins are even more indicated than for the rest of the population.


Up to now this blog could have been written ten years ago with no change. Recently two issues have been identified: what level of hypertension needs treatment and with what drug.


New guidelines were issued in 2017 by the ACC/AHA:

Blood pressure categories in the new guideline are:

  • Normal: Less than 120/80 mm Hg;
  • Elevated: Systolic between 120-129 and diastolic less than 80;
  • Stage 1: Systolic between 130-139 or diastolic between 80-89;
  • Stage 2: Systolic at least 140 or diastolic at least 90 mm Hg;


These ‘limits’ were based on a review of many papers and are lower than previously used.  The second interesting publication in the Lancet showed the risk of cardiovascular events can be reduced by antihypertensive drugs regardless of an individual’s blood pressure. Ie there is no ‘safe’ blood pressure and lowering blood pressure in the ‘normal’ range may be beneficial.  This opens Pandora’s box and the NHS could not cope with prescribing and monitoring all adults, but from an individual’s perspective there is something to think about.

Finally, which drug. This will normally be up to the doctor and for twenty years I have seen protocol after protocol, but there is still such a range of preferences such that if I diagnose hypertension I let the GP decide. It is irrefutable that one drug normally is enough and we only add a second if one doesn’t lower the pressure enough.  The LEGEND-HTN study has attempted to answer the question of which drug and interestingly come up with thiazide diuretics – the cheap and original drug with good tolerance and minimal side effects. Maybe one day they will be sold over the counter and we will all be taking them