What is a stroke?
1 in 5 people will have a stroke at some point during their life.
A stroke occurs when blood supply to the brain is disrupted. Blood is transported to the brain by blood vessels called arteries. Blood contains important nutrients and oxygen to your brain. This may stop moving through an artery because the artery bursts (hemorrhagic stroke) and or the artery is blocked (ischemic stroke) When the brain cells are not getting enough nutrients or oxygen, they die. The area where the brain has been damaged is called a cerebral infarct.
A stroke is a medical emergency.
Knowledge is power. Recognising the signs
& acting quickly is crucial.
Signs of a stroke:
- Facial weakness: Can the person smile? Has their eye or mouth drooped?
- Arm weakness: Can they lift both arms? Is one arm weak, drooping or numb?
- Speech difficulty: Is speech slurred? Do they understand you?
- Time: It is time to call 112 or 999 if you see any of these signs. Time is critical.
- Weakness or paralysis on either one or both sides of the body
- Unexplained fall, loss of balance or coordination
- Loss of vision in one of both eyes, sudden blurred vision
- Sudden confusion or memory loss
- A sudden, severe headache, dizziness
Types of stroke:
Ischaemic stroke: This is the most common type of stroke. An ischaemic stroke is caused by a blockage cutting off the blood supply to part of the brain which damages brain cells. An example of this is the narrowing of arteries. Damage to brain cells can affect how the body works.
There are two types of Ischemic strokes.
- Embolic Stroke: This is caused by a blood clot or plaque fragment forms somewhere else in the body, usually the heart. The clot moves through the blood stream to the brain. When the clot arrives to the brain, it is too big to pass through a blood vessel and gets stuck. This stops the blood passing through and causes an embolic stroke.
- Thrombotic stroke: This occurs when a clot forms in an already narrowed or damaged artery within the brain and blocks the supply of blood to that area. Atherosclerosis (the build-up of a fatty substance called plaque) is the most common cause of narrowing of the arteries. Lifestyle risk factors can contribute to Atherosclerosis including high blood pressure, high cholesterol, obesity, smoking, diabetes and reduced physical activity.
Haemorrhagic stroke: Haemorrhagic stroke is caused when a weakened blood vessel that supplies the brain ruptures and bleeds, stopping the delivery of oxygen and nutrients. The interrupted blood flow causes damage to the brain.
There are two types of haemorrhagic strokes, described by their location in the brain.
- Intracerebral haemorrhage: This occurs when an artery inside the brain bursts and bleeds into the brain. High blood pressure contributes to weak arteries over time.
- Subarachnoid haemorrhage: This is bleeding on the subarachnoid space. There are 3 layers of membrane (or meninges) that cover the brain. A subarachnoid haemorrhage is a bleed that happens between the layer closest to the brain and the second layer.
Transient Ischaemic Attack (TIA)
A Transient Ischaemic Attack, (TIA) also known as a ‘mini stroke’ occurs when blood supply to the brain is blocked temporarily, often for a few minutes.
The signs of a TIA are similar to a stroke but disappear within a short time. This includes weakness along one side of the body, a brief loss of speech or vision.
After a TIA, the risk of stroke is higher. A TIA can be a warning that a major stroke may occur. It is often an opportunity to prevent a stroke happening, with investigation, treatment and management of risk factors.