A stroke is a medical emergency that happens when blood flow to part of the brain is blocked or when a blood vessel in the brain bursts. Quick action matters because brain cells can be damaged very quickly.
What is a stroke?
The brain needs a steady blood supply to keep working properly. If that blood flow is interrupted, parts of the brain can stop working as they should.
This can affect:
- speech
- movement
- balance
- alertness
- vision
What signs might you notice?
Common warning signs can include:
- sudden facial drooping
- weakness or numbness in one arm or one side of the body
- slurred speech or trouble speaking
- sudden confusion
- sudden trouble walking or balancing
- sudden severe headache
Sudden double vision can be described as diplopia. It can be another important stroke-style warning sign.
Poor coordination or unusually clumsy movement can also be described as ataxia, especially when balance and movement are affected.
If one side of the body is not moving at all, that can be described as hemiplegia, which is more severe than general weakness.
Sometimes a stroke affects language more than speech clarity. Aphasia can make it hard to find words, understand language, read, or write.
Slurred speech can also be described as dysarthria. That term is mainly about how words sound rather than how language itself is understood or used.
One of the simplest ways to look for common signs is FAST.
What does FAST mean?
FAST stands for face, arms, speech, and time.
- face: one side may droop
- arms: one arm may be weak or drift down
- speech: words may be slurred or confused
- time: call
000immediately
What about a transient ischaemic attack (TIA)?
A Transient Ischaemic Attack (TIA) can cause similar stroke-style signs that settle after a short time, but it still needs urgent medical assessment because it can be a warning sign of future stroke.
Why is stroke an emergency?
Stroke treatment is time-sensitive. The longer the brain goes without the right blood flow, the greater the risk of permanent damage.
That is why you should not wait to see if the signs pass.
What should you do in first aid?
- Call
000immediately. - Keep the person safe and reassure them.
- Note when the signs started, if you know.
- Watch breathing and responsiveness.
- If the person becomes Unresponsive and is not breathing normally, start CPR.
Do not give food, drink, or medicine unless instructed by a medical professional.
Why do neurological signs matter?
A stroke affects the brain, so changes in alertness, speech, movement, and behaviour matter. That is why pages such as FAST, AVPU, and Neurological Assessment are relevant in this cluster.
Quick answer
A stroke happens when blood flow to part of the brain is blocked or a blood vessel bursts. It is a medical emergency, and the key first aid step is to recognise the signs quickly and call 000 without delay.
How this page is checked
Publisher: First Aid Glossary Editorial Team
Last reviewed: 28 April 2026
Reviewed against: ANZCOR Guideline 9.2.2 – Stroke, Healthdirect Australia stroke information, and Triple Zero emergency-call guidance.
This page is educational and explains first aid language in plain English. It is not personal medical advice, diagnosis, or a replacement for accredited first aid training. In an emergency in Australia, call Triple Zero (000).
Sources reviewed
Reviewed against Australian first aid and emergency guidance by the First Aid Glossary Editorial Team. This article is general information and does not replace emergency-operator directions, professional medical advice or hands-on first aid training.
