Hypertension Teachings Article

How is high blood pressure diagnosed

A one-off blood pressure reading which is high does not mean that you have 'high blood pressure'. Your blood pressure varies throughout the day. It may be high for a short time if you are anxious, stressed, or have just been exercising.

You are said to have 'high blood pressure' (hypertension) if you have several blood pressure readings which are high, and which are taken on different occasions, and when you are relaxed. If one reading is found to be high, it is usual for your doctor or nurse to advise a time of observation. This means several blood pressure checks at intervals over time. The length of the observation period varies depending on the initial reading, and if you have other health risk factors. For example, say a first reading was mildly high at 150/94. If you are otherwise well, then a period of several months 'observation' may be advised. A blood pressure reading may be taken every few weeks or so. The observation period is also a good time to change any lifestyle factors which can reduce blood pressure (see below). If the blood pressure readings remain high after an 'observation period' then treatment with medication may be advised (see below).

However, if you have diabetes, or have recently had a heart attack, you may be advised to have blood pressure checks fairly often over the next week or so. Also, treatment with medication may be considered at an earlier stage if the readings remain high.

Some people are given (or buy) machines to monitor blood pressure at home (home monitoring) or when they are going about doing their everyday activities (ambulatory monitoring). One reason this may be advised is because some people become anxious in medical clinics which can cause the blood pressure to rise. (This is called 'white coat' hypertension.) Home or ambulatory monitoring of blood pressure may show that the blood pressure is normal when you are relaxed.