I don't know much, I know there is 5 categories. 1 being the most serious, 5 the lowest...

Generally heart attacks, asthma attacks, car crashes etc those with life threatening illnesses are at a cat 1. They go in straight away.

I think 2 has to be seen in 15-30 mins. And it kinda goes like that.

Sorry cant really explain it too well. Hopefully someone else comes in