High blood pressure and stroke

A stroke, sometimes called a “ brain attack”, occurs when blood flow to an area in the brain is cut off. As a result  the brain cells  - deprived of oxygen and glucose - die. If not caught early, permanent brain damage can result. Every year, more than 150,000 people in the UK have a stroke. 

People who have high blood pressure (hypertension) are four to six times more likely to have a stroke. Over time, hypertension leads to atherosclerosis and hardening of the large arteries. This in turn leads to blockage and weakening of the walls of the small blood vessels in the brain that may then balloon and burst. The risk of stroke is directly related to how high the blood pressure is.

How does a stroke occur?

There are two types of stroke:

• Ischaemic stroke is similar to a heart attack, except it occurs in the blood vessels of the brain. Clots can form either in the brain’s blood vessels, in blood vessels leading to the brain, or even blood vessels elsewhere in the body which then travel to the brain. These clots block blood flow to the brain’s cells. Ischaemic stroke can also occur when too much plaque (fatty deposits and cholesterol) clogs the brain’s blood vessels. About 80 per cent of all strokes are ischaemic stroke.
• Haemorrhagic (heh-more-raj-ik) strokes occur when a blood vessel in the brain breaks or ruptures. The result is blood seeping into the brain tissue, causing damage to brain cells. The most common causes of haemorrhagic stroke are high blood pressure and brain aneurysms. An aneurysm is a weakness or thinness in the blood vessel wall that causes it to balloon outward.

Signs of stroke

If you experience any of the following signs you or a loved one may be having a stroke, call 999 immediately.

• Sudden numbness or weakness in the face, arm or leg (especially on one side of the body)
• Sudden blurred vision or decreased vision in one or both eyes
• Sudden inability to move part of the body (paralysis)
• Sudden dizziness or headache with nausea and vomiting
• Difficulty speaking or understanding words or simple sentences
• Difficulty swallowing
• Dizziness, loss of balance or poor coordination
• Brief loss of consciousness
• Sudden confusion

The Fast  - Face Arm Speech Time - test is used by paramedics to diagnose stroke prior to a person being admitted to hospital. Fast is an assessment of three specific symptoms of stroke:

A transient ischaemic attack (TIA), often called a “mini-stroke”, may be a warning of an impending stroke. It typically consists of the same signs and symptoms of stroke, but the symptoms are temporary. It occurs when blood flow to a certain part of the brain is cut off for a short period of time, usually 15 minutes or less. A TIA can occur anywhere from a few minutes to several months before a stroke. A TIA is a painless episode but it is a warning that something is wrong. It should be treated as seriously as a stroke.