What is Stroke?

A stroke or cerebrovascular accident occurs when blood flow to the brain is disrupted.

In this article:

• What is a stroke?
• Types of stroke
• Stroke signs
• Stroke warning signs
• Stroke risk factors  

What is a stroke?

If the brain does not receive oxygen via the blood, brain cells can die resulting in damage to certain areas of the brain.

Damaged brain cells can sometimes repair themselves. If brain cells die, the damage is permanent. People who have had a stroke can have difficulty walking, speaking and thinking.

Blood flow through the arteries can be disrupted by a clot or blocked by a build up of plaque in the arteries. The arteries can also break or burst.
 
It is important to seek medical help immediately as other brain cells are then at risk of death. Timely treatment can help stop further damage from stroke.

Types of stroke

Ischaemic strokes

Ischaemic strokes are the most common form of stroke. An ischaemic stroke occurs when a clot blocks a blood vessel or artery in the brain starving it of nutrients and oxygen.

The brain cells then die causing damage to the area. Brain cells can die very quickly in the minutes or hours after a stroke.

Prompt treatment can possibly minimise the extent of damage to other areas of the brain where blood supply is reduced.

Haemorrhagic stroke

A haemorrhagic stroke is less common and occurs when an artery in the brain leaks or erupts damaging and exerting pressure on the surrounding brain tissue.

Haemorrhagic stroke has been associated with high blood pressure or conditions of the blood vessels of the brain.

Stroke signs

A stroke affects everyone differently. Symptoms depend on the type of stroke, the area affected and the extent of damage done to the brain.

Anyone who experiences signs of stroke should seek medical help immediately by calling 000.

Prompt medical treatment can increase a person’s chances of survival and help reduce severity of damage from stroke.

Signs of stroke may include a combination or any one of the signs mentioned here:

• Facial weakness, eye and mouth appear to have drooped

• Numbness or paralysis of the face, arms and legs on one or both sides of the body

• Difficulty speaking, slurred speech

• Disturbed vision

• Confusion and problems understanding

• Headache, sudden and severe

• Dizziness, poor balance and/or co-ordination

• Problems swallowing

Stroke warning signs

The body sometimes shows early warning signs of stroke called a Transient Ischaemic Attack (TIA) or mini stroke.

This episode is similar to a stroke except the symptoms disappear within 24 hours. A TIA is an important sign of a possible future stroke and a medical emergency.

A person may appear to get better. Even if signs disappear, seek medical help immediately by calling 000.

A doctor will want to investigate the cause of the TIA and may prescribe medications or treatment to lower the risk of another TIA or future stroke.

Stroke risk factors

There are many risk factors for stroke including:

•  High blood pressure
•  Cigarette smoking
•  High blood cholesterol
•  Diabetes
•  Heart and blood vessel disease
•  Diabetes
•  Excessive alcohol intake
•  Increasing age
•  Irregular heart beat (atrial fibrillation)
•  Previous transient ischaemic attack (TIA) 

Source Heart Foundation Australia, 2008

Helpful resources

• For more information on stroke visit The National Stroke Foundation at www.strokefoundation.com.au or call the StrokeLine on 1800787653.   

Related articles

• Common effects and complications of stroke
• Stroke treatment and prevention
• Going home after stroke
• What home care aids can help with stroke?

References
The National Stroke Foundation
What is a stroke?
Accessed 13/08/08

Heart Foundation, Australia
Reducing Risk of Stroke
Accessed 13/08/08