When you have high blood pressure, early diagnosis and treatment is vital to prevent long-term damage to your circulation health. Diet and lifestyle should always come first, and hypertension treatment guidelines suggest the benefits of drug treatment must be weighed up against any potential side effects.
Does high blood pressure always need drug treatment?
Your doctor will measure your blood pressure several times before deciding whether or not to prescribe anti-hypertensive medication. This is to ensure your BP is consistently high and not just rising as a result of visiting the surgery – an effect known as white coat hypertension.
If your BP is 140/90 mmHg or higher at the first reading, your doctor will recheck it two or three times during your appointment, once you are more relaxed. The lower of the measurements is recorded as the clinic blood pressure reading.
If this lower reading is 140/90 mmHg or higher, your doctor will arrange for you to wear a 24 hour monitor to see how your blood pressure varies during the day and night (ambulatory blood pressure monitoring, or ABPM).
Home blood pressure monitoring can also be used. If you have a home blood pressure monitor, then record your readings and take them to the surgery with you.
Your doctor may ask you to return to check your blood pressure again. In the meantime, you could avoid the need for medication by following a lower salt DASH diet, eating foods that reduce blood pressure, cutting back on alcohol and caffeine and avoiding smoking.
If you have severe hypertension, drug treatment may be started immediately, without waiting for the results of ABPM or home blood pressure monitoring. If your blood pressure is very high, you may even be admitted to hospital to bring it down in a controlled fashion and to look for any underlying causes that may also need treatment, such as kidney disease (see Secondary Hypertension).
The benefits of hypertension treatment
It may seem surprising, but just a 2 mmHg reduction in your systolic BP (upper reading) can reduce your risk of cardiovascular disease by 7% – 10%. Similarly, a prolonged reduction of 5 mmHg in your diastolic blood pressure (lower reading) is associated with 34% fewer strokes and 21% fewer heart attacks. Benefits increase as blood pressure is reduced further into the normal range.
Over all, large clinical trials have now confirmed that treating high blood pressure to bring it down to normal levels can reduce your risk of experiencing:
- a stroke by 35-40%
- a heart attack by 20-25%
- heart failure by more than 50%.
If you also have diabetes, then good control of your blood pressure is even more important, and can reduce your risk of experiencing any diabetes-related complications by at least a quarter.
Click here for more information on why it is important to treat hypertension to prevent complications.
Your target blood pressure
Blood pressure changes with age, and your target blood pressure will depend on how old you are.
If you are under 80 years of age: the usual target is to bring your blood pressure down to less than 140/90 mmHg. Results of recent trials suggest that a better target average blood pressure, during your usual waking hours, is below 135/85 mmHg.
If you have diabetes or chronic kidney disease, however, your goal level is usually lower at less than 130/80 mmHg.
If you are aged 80 years or over: the target blood pressure is usually below 145/85 mmHg during waking hours. Going too low is not ideal, as this could cause dizziness, resulting in a fall. However, recent studies suggest that an even lower blood pressure target of less than 120 mmHg may be more appropriate for older people aged 75 years plus.
Only 30-40% of people with hypertension achieve their goal blood pressure. This is due to a number of reasons, including:
– not following diet and lifestyle advice
– not taking their medicines as prescribed
– not monitoring their blood pressure themselves, at home
– not going back to see their doctor if their readings are not well controlled.
Perhaps the biggest problem is that having a high blood pressure does not cause significant symptoms, even when it is dangerously high, so there is little incentive to do anything about it.
Hypertension treatment guidelines chart
Your doctor will follow accepted guidelines when deciding whether or not you need prescribed antihypertensive medication.
The European Society of Hypertension and the European Society of Cardiology, for example, recommend that treatment is based on your blood pressure reading and whether or not you have other risk factors (such as obesity, smoking, an irregular heart beat) and whether or not you have diabetes, established heart, kidney or other organ disease, as shown in the following table:
Your doctor may also calculate your risk of having a heart attack or stroke over the next 10 years and start treatment sooner rather than later if your 10-year risk is at least 20%. This calculation is based on factors such as your age, gender, blood pressure, weight and cholesterol.
Click here to calculate your own risk of a heart attack or stroke if you have the results of a recent full health check-up (systolic blood pressure and cholesterol/HDL ratio).
Blood pressure treatment guidelines: Diet and lifestyle
If you have no other risk factors then your doctor will first recommend diet and lifestyle changes:
- If you smoke, do your utmost to quit
- Restrict your salt intake to less than 5g – 6g per day
- Limit alcohol to 20g – 30g/day for men, 10g – 20g/day for women
- Avoid excess caffeine
- Eat more fruit, vegetables and dairy products by following a DASH diet
- Maintain a healthy weight (BMI less than 25 Kg/M2), with a waist circumference of <102cm for men, <88cm for women
- Exercise briskly for at least 30 minutes on 5 to 7 days of the week.
The RESPeRATE guided breathing device is also effective.
If you have other circulatory risk factors such as diabetes, heart or kidney disease, secondary hypertension, or if your blood pressure remains high, then medication is usually started straight away, in addition to these lifestyle changes – not instead of them.
Which antihypertensive drugs are used?
Six main types or class of blood pressure drugs are used:
- thiazide-like diuretics
- alpha blockers
- calcium-channel blockers (calcium antagonists)
- angiotensin-converting enzyme (ACE) inhibitors
- angiotensin-II receptor blockers (ARBs).
Your first treatment is selected depending on your age, other health factors and your ethnicity – there is evidence that different treatments work better depending on whether you are of Caucasian, African or Caribbean family origin.
How many blood pressure medicines do you need?
You may be started on a single drug if your blood pressure elevation is ‘mild’ and your risk of cardiovascular disease is low. If your blood pressure is significantly raised or your risk of cardiovascular disease is high, you may be started on a two-drug combination. These doses are then increased or other drugs added in as needed.
Only around one in ten people taking blood pressure treatments remain well controlled on just one drug (monotherapy).
Most people (65%) need two classes of drugs to reach their blood pressure treatment target.
A quarter (25%) will need three classes of antihypertensive drug to achieve good control.
The advantage of starting on a combination of two drugs is that they work in different ways. This helps to achieve a more rapid response, is more likely to bring your blood pressure down to your goal level, and uses lower doses which are less likely to produce side effects. Where possible, your doctor will select a drug or combination of drugs that you only need to take once a day. This makes it easier to remember to take your treatment regularly, every day, by getting into a routine.
Which blood pressure drugs are best?
The results from a large number of randomized trials show that the main benefits of antihypertensive treatment are due to achieving a lower blood pressure in itself, and are largely independent of the drugs used. The advantage of having six classes to choose from is that your doctor can usually find a combination that controls your blood pressure and which suits you as an individual, without causing unwanted side effects.
A large analysis of results from 42 trials, involving almost 11,000 people, showed that combining two different types of antihypertensive drug produces better blood pressure control than escalating the dose of one single medicine. The average effectiveness of each type of drug on its own (monotherapy), or when combined with any other class of drug was as follows:
When your blood pressure is well controlled on two or more drugs, these fixed doses are taken as one single combination tablet where possible.
If you don’t reach your target blood pressure with a two-drug combination at full doses, your doctor may switch you to another two-drug combination or add in a third drug.
Not all drugs can be taken together, however. The following diagram shows which combinations are preferred and which is not recommended.
Green continuous lines: preferred combinations
Green dashed line: useful combination (with some limitations)
Black dashed lines: possible but less well-tested combinations
Red continuous line: not a recommended combination.
An angiotensin-receptor blocker, for example, may be combined with a thiazide diuretic and/or a calcium channel blocker/antagonist, but not with an ACE inhibitor.
How long do you need to take blood pressure treatments?
Although blood pressure treatment is often needed for the rest of your life, many people successful make diet and lifestyle changes that allow their doctor to reduce their medicine doses, cut the number of drugs required, or even stop them altogether.
Don’t adjust your medication yourself but be guided by your doctor. Blood pressure treatment is life-saving as it helps to prevent a future heart attack, stroke, kidney disease and eye complications.
Feel free to add comments and ask general questions about blood pressure treatments below to share your thoughts and experience. For specific advice relating to your own medicines, check the Patient Information Leaflet inside the pack, and ask your doctor or pharmacist.
If your blood pressure is raised, self-monitoring is key to maintaining good control.
Click here for advice on choosing a blood pressure monitor to use at home.
Image credits: kraevski_vitaly; piggu / shutterstock; ESH/ESC Guidelines; pixabay