It can be, but, for the layman, an excellent guide to diagnosing stroke in friends or acquaintences is contained within the acronym S.T.R....
S = Smile... ask the person to smile. This is difficlut to do for a person who has experienced even a small stroke.
T = Talk... ask the person to repeat a simple sentence ("It's a sunny day outside"). Stroke sufferers often become confused.
R = Raise both arms ...
If the person has any diffiuclty with any of these, call emergency response immediately. Better a flase alarm than have the person die of undiagnosed stroke.
A new test has just been added...Stick out your tongue... Ask the person to 'stick' out his tongue.. If the tongue is 'crooked', if or it goes to one side or the other,that
is also an indication of a stroke...