What do they use to put you under general anesthesia and how do they make sure youre ok the whole time for surgery? no one has ever really explained it to me before and now im nervous ahead of next surgery?

A number of drugs given via IV or inhaled that can provide various levels of anesthesia. There are different levels and these target removing awareness and relaxing the body. For most surgery they take your system deep enough that they must assist your breathing with a machine. They continuously monitor your heart rate, lung and oxygen levels and reflexes that verify you are in a deep level .