High blood pressure (hypertension) is a blood pressure that is 140/90 mm Hg or above each time it is taken at the GP surgery, or home or ambulatory readings where the average is more than 135/85 mm Hg. That is, it is sustained at this level.

The higher number is called the systolic blood pressure, and the lower number is the diastolic blood pressure. The ideal blood pressure is between 90/60mmHg and 120/80mmHg.

High blood pressure is only diagnosed if there are several blood pressure readings that are high, taken on different occasions, and when a person is relaxed.

Symptoms

The vast majority of people with high blood pressure do not know they have it, until it causes a complication such as a stroke or heart attack. Usually high blood pressure is only picked up if blood pressure is checked routinely, or as part of checks for another medical problem.

Occasionally, symptoms of high blood pressure may include:

• Headaches.
• Dizziness.
• Affected vision.
• Changes in the blood vessels at the back of the eye.

Other than the blood pressure reading being high, there isn’t usually anything for the doctor to find on examination either. If blood pressure has been high for some time, or very high, there can be changes in the blood vessels at the back of the eye.

Diagnosis

Unless a single level is extremely high, high blood pressure will not be diagnosed without an average of several readings, usually from home or ambulatory measurements. Blood pressure recording outside of the doctor’s surgery is recommended in most people who are suspected of having high blood pressure.

One reason for this is because some people become anxious in medical clinics. This can cause the blood pressure to rise. (This is often called white coat hypertension.) Home or ambulatory monitoring of blood pressure may show that the blood pressure is normal when a person is relaxed.

However, if a person has diabetes, or has recently had a heart attack or stroke, blood pressure checks may be advised more often over the following week or so. Treatment with medication is usually considered at an earlier stage if the high blood pressure readings remain high.

Problems associated with high blood pressure

High blood pressure (hypertension) is a risk factor for developing serious health problems sometime in the future. High blood pressure over a long period of time may do some damage to the blood vessels (arteries) and put a strain on the heart. In general, the higher the blood pressure, the greater the health risk.

Cardiovascular disease is the biggest risk from having high blood pressure. Cardiovascular diseases are diseases of the heart (cardiac muscle) or blood vessels (vasculature). This usually means diseases of the heart or blood vessels that are caused by atheroma.

Patches of atheroma are like small fatty lumps that develop within the inside lining of blood vessels (arteries). Atheroma is also known as atherosclerosis and hardening of the arteries.

Cardiovascular diseases that can be caused by atheroma include:

• Angina.
• Heart attack.
• Stroke.
• Transient ischaemic attack (TIA).
• Peripheral arterial disease.

If you need more information regarding Hypertension then you can visit the NHS website here.