A post mortem on former foreign secretary Robin Cook has found he died from hypertensive heart disease.
High blood pressure is a risk factor for heart disease and stroke
Hypertension, or high blood pressure forces the heart to work harder and harder to pump enough blood and oxygen to the body's organs and tissues to meet their needs.
HIGH BLOOD PRESSURE DEFINITION
Blood pressure at or above 140mm Hg (millimetres of mercury) when the heart is contracting - systolic
Blood pressure at or above 90mm Hg when the heart is relaxing - diastolic
When this happens for an extended time, the heart enlarges and weakens.
While a slightly enlarged heart may work well, one that is significantly enlarged has a hard time meeting the demands put on it.
Arteries also suffer the effects of high blood pressure, becoming scarred, hardened and less elastic.
Though this hardening of the arteries often occurs with age, high blood pressure accelerates the process.
Another risk is that a blood clot may lodge in an artery narrowed by fatty deposits, called atherosclerosis, blocking blood supply.
Hypertension exists where the pressure at which blood is pushing against blood vessel walls is consistently above average.
It is measured in and is defined in an adult as a blood pressure equal to or above 140mm Hg when the heart is contracting - systolic - and 90mm Hg when the heart is relaxing - diastolic.
In 90 to 95% of cases of high blood pressure, the cause is unknown.
In the remaining cases, high blood pressure is a symptom of a recognisable underlying problem such as a kidney abnormality, tumour of the adrenal gland or congenital defect of the body's main blood artery the aorta.
When the root cause is corrected, blood pressure usually returns to normal. This type of high blood pressure is called secondary hypertension.
The only way to find out if you have high blood pressure is to have your blood pressure checked. A doctor or other qualified health professional should check a patient's blood pressure at least once every two years.
The condition can be effectively controlled using drugs - usually ACE inhibitors or beta-blockers.
But if it is uncontrolled, it can also be linked to an increased risk of stroke, kidney failure and damage to the eyes.