What is a stroke?

What is a stroke?
A stroke is a life-threatening medical emergency that happens when the blood supply to part of the brain is cut off.
 The blood supply may be cut off by a blood clot or from a burst blood vessel.
 A person having a stroke may lose control over their movement, perception and speech. They may also lose consciousness.
 Prompt hospital treatment is essential for stroke survival.
Clots near the brain
Over 80% of all strokes are due to blockage of the oxygen-rich blood flowing to the brain. Called ischaemic strokes, they are triggered by either a thrombus, which is a stationary clot that forms in a blood vessel, or an embolus, a clot that travels through the bloodstream and becomes lodged in a vessel.
This type of stroke is often preceded by brief transient ischaemic attacks, or TIAs, which are episodes of inadequate blood flow that may produce these symptoms:
•Sudden physical weakness
•An inability to talk
•Double vision
•Dizziness.
Symptoms of a TIA fully resolve within 24 hours. However, because these may be signs of an impending stroke, take them seriously and seek medical advice immediately.
 With a TIA, circulation and the vital oxygen supply are quickly restored and lasting brain and nerve damage is avoided. With any stroke, however, the interruption of blood flow lasts long enough to kill brain cells, producing irreversible damage.