I'm sorry about your gran.
The reason for stroke
occuring is primarily a blood clot in one of the blood vessels in the brain. This clot stops blood & oxygen
flowing to the areas of the brain and it can cause irreversible damage to the brain tissue. The longer the clot remains, the more permanent the damage to the brain.
By achieving medical help
(and preferably the correct help ie stroke unit
) rapidly, special medication can be administered to break up the clot and restore blood to the damaged area of the brain.
Some strokes happen during sleep and symtpoms are not recognised until the clot has been in situ for hours - therefore not everyone can obtain help as rapidly - thus affecting the success of medical treatment and decreasing the chances of a good recovery.